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OT: mpg question
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Scott
May 14, 2022, 5:21:00 AM5/14/22
to
I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
the drive computer at the start. On the way north, I was running late
and driving a bit faster than usual. I also got caught in a traffic
jam on the M8. When I arrived I checked the display and it showed
52.5 mpg. l reset the drive computer before returning. I drove more
slowly on the way home, without the traffic jam, and got 48.8 mpg.
Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
How can this be? I thought slowing down saved fuel. The only
explanation I can think of is that I may have been driving into the
wind on the way south. Could this account for the variation?
the drive computer at the start. On the way north, I was running late
and driving a bit faster than usual. I also got caught in a traffic
jam on the M8. When I arrived I checked the display and it showed
52.5 mpg. l reset the drive computer before returning. I drove more
slowly on the way home, without the traffic jam, and got 48.8 mpg.
Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
How can this be? I thought slowing down saved fuel. The only
explanation I can think of is that I may have been driving into the
wind on the way south. Could this account for the variation?
Clive Arthur
May 14, 2022, 5:41:49 AM5/14/22
to
done a few times. Yes, I'm pretty sure it's the wind that makes the
difference.
--
Cheers
Clive
Tim Lamb
May 14, 2022, 6:30:19 AM5/14/22
to
In message <t5ntgp$sf8$1...@dont-email.me>, Clive Arthur
<cl...@nowaytoday.co.uk> writes
A pair of wing mirrors was once measured as using 2bhp at 60mph.
>
--
Tim Lamb
<cl...@nowaytoday.co.uk> writes
>
--
Tim Lamb
The Natural Philosopher
May 14, 2022, 6:44:05 AM5/14/22
to
lost to drag. Over 50mph most of the energy loss is drag.
I cant be arsed to work out actual numbers, but its moire than plausible.
I remember many years ago my Triumph Spitfire - which used to do about
35mpg, had to make a 90 mile drive over fresh snow on new years very
early day. Any heavy throttle or brakes sent the car sideways. I made
it, never more than 50mph, and clocked over 50mpg...
Before that a friend had some old Hillman and we drove North with a
following wind at never more than 55mph, and south again into the wind.
Again the mpg was significantly different.
--
“It is dangerous to be right in matters on which the established
authorities are wrong.”
― Voltaire, The Age of Louis XIV
Jeff Gaines
May 14, 2022, 7:01:33 AM5/14/22
to
On 14/05/2022 in message <7lsu7h9eb2k80alhu...@4ax.com>
North is up hill all the way, South is down hill.
--
Jeff Gaines Dorset UK
There are 10 types of people in the world, those who do binary and those
who don't.
--
Jeff Gaines Dorset UK
There are 10 types of people in the world, those who do binary and those
who don't.
Scott
May 14, 2022, 7:13:23 AM5/14/22
to
away from motorways. .
NY
May 14, 2022, 7:29:20 AM5/14/22
to
"Scott" <newsg...@gefion.myzen.co.uk> wrote in message
news:qj3v7hth0loh4r8u1...@4ax.com...
well-publicised tour around the UK by two "feather-footed" drivers who tried
to use as little fuel as possible. They apparently averaged 90 mpg. I think
I tend to drive fairly economically (gentle acceleration, keep to speed
limits, lift off power early to lose speed rather than driving right up to a
junction and then braking hard). But the best I've averaged on a tankful of
fuel is about 60 mpg - and that may partly have been due to random filling
differences (different pumps cut out at different points). The average over
about 170,000 miles (*) is 54 mpg. It's possible that the car used for the
record had a less powerful engine (if that makes it more efficient) and I
couldn't find any mention of whether the drivers had a lower self-imposed
maximum speed to use less fuel. Maybe they only did each leg of the journey
on a day that the wind was predominantly behind them ;-)
(*) Mainly motorway, A road and country lanes, but almost no stop-start in
heavy traffic.
news:qj3v7hth0loh4r8u1...@4ax.com...
>>Before that a friend had some old Hillman and we drove North with a
>>following wind at never more than 55mph, and south again into the wind.
>>Again the mpg was significantly different.
>
> My friend got it to 60 mpg with some very skilful and cautious driving
> away from motorways.
My car (Peugeot 308 with a diesel engine) was the subject of a
>>following wind at never more than 55mph, and south again into the wind.
>>Again the mpg was significantly different.
>
> My friend got it to 60 mpg with some very skilful and cautious driving
> away from motorways.
well-publicised tour around the UK by two "feather-footed" drivers who tried
to use as little fuel as possible. They apparently averaged 90 mpg. I think
I tend to drive fairly economically (gentle acceleration, keep to speed
limits, lift off power early to lose speed rather than driving right up to a
junction and then braking hard). But the best I've averaged on a tankful of
fuel is about 60 mpg - and that may partly have been due to random filling
differences (different pumps cut out at different points). The average over
about 170,000 miles (*) is 54 mpg. It's possible that the car used for the
record had a less powerful engine (if that makes it more efficient) and I
couldn't find any mention of whether the drivers had a lower self-imposed
maximum speed to use less fuel. Maybe they only did each leg of the journey
on a day that the wind was predominantly behind them ;-)
(*) Mainly motorway, A road and country lanes, but almost no stop-start in
heavy traffic.
The Natural Philosopher
May 14, 2022, 8:25:01 AM5/14/22
to
On 14/05/2022 12:01, Jeff Gaines wrote:
> On 14/05/2022 in message <7lsu7h9eb2k80alhu...@4ax.com>
> Scott wrote:
>
>> I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
>> the drive computer at the start. On the way north, I was running late
>> and driving a bit faster than usual. I also got caught in a traffic
>> jam on the M8. When I arrived I checked the display and it showed
>> 52.5 mpg. l reset the drive computer before returning. I drove more
>> slowly on the way home, without the traffic jam, and got 48.8 mpg.
>>
>> Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
>>
>> How can this be? I thought slowing down saved fuel. The only
>> explanation I can think of is that I may have been driving into the
>> wind on the way south. Could this account for the variation?
>
> North is up hill all the way, South is down hill.
>
well its actually the other way, north is down wind and south is into
> On 14/05/2022 in message <7lsu7h9eb2k80alhu...@4ax.com>
> Scott wrote:
>
>> I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
>> the drive computer at the start. On the way north, I was running late
>> and driving a bit faster than usual. I also got caught in a traffic
>> jam on the M8. When I arrived I checked the display and it showed
>> 52.5 mpg. l reset the drive computer before returning. I drove more
>> slowly on the way home, without the traffic jam, and got 48.8 mpg.
>>
>> Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
>>
>> How can this be? I thought slowing down saved fuel. The only
>> explanation I can think of is that I may have been driving into the
>> wind on the way south. Could this account for the variation?
>
> North is up hill all the way, South is down hill.
>
the wind. which was around 20mph+ yesterday and broadly southerly
--
If you tell a lie big enough and keep repeating it, people will
eventually come to believe it. The lie can be maintained only for such
time as the State can shield the people from the political, economic
and/or military consequences of the lie. It thus becomes vitally
important for the State to use all of its powers to repress dissent, for
the truth is the mortal enemy of the lie, and thus by extension, the
truth is the greatest enemy of the State.
Joseph Goebbels
AnthonyL
May 14, 2022, 8:27:39 AM5/14/22
to
On 14 May 2022 11:01:29 GMT, "Jeff Gaines"
--
AnthonyL
Why ever wait to finish a job before starting the next?
<jgaines...@yahoo.co.uk> wrote:
>On 14/05/2022 in message <7lsu7h9eb2k80alhu...@4ax.com>
>Scott wrote:
>
>>I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
>>the drive computer at the start. On the way north, I was running late
>>and driving a bit faster than usual. I also got caught in a traffic
>>jam on the M8. When I arrived I checked the display and it showed
>>52.5 mpg. l reset the drive computer before returning. I drove more
>>slowly on the way home, without the traffic jam, and got 48.8 mpg.
>>
>>Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
>>
>>How can this be? I thought slowing down saved fuel. The only
>>explanation I can think of is that I may have been driving into the
>>wind on the way south. Could this account for the variation?
>
>North is up hill all the way, South is down hill.
>
I turn my map through 180deg when going North. Saves a small fortune.
>On 14/05/2022 in message <7lsu7h9eb2k80alhu...@4ax.com>
>Scott wrote:
>
>>I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
>>the drive computer at the start. On the way north, I was running late
>>and driving a bit faster than usual. I also got caught in a traffic
>>jam on the M8. When I arrived I checked the display and it showed
>>52.5 mpg. l reset the drive computer before returning. I drove more
>>slowly on the way home, without the traffic jam, and got 48.8 mpg.
>>
>>Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
>>
>>How can this be? I thought slowing down saved fuel. The only
>>explanation I can think of is that I may have been driving into the
>>wind on the way south. Could this account for the variation?
>
>North is up hill all the way, South is down hill.
>
--
AnthonyL
Why ever wait to finish a job before starting the next?
alan_m
May 14, 2022, 8:45:24 AM5/14/22
to
On 14/05/2022 12:13, Scott wrote:
>
> My friend got it to 60 mpg with some very skilful and cautious driving
> away from motorways. .
I find motorways give me the best mileage - no corners or winding lanes.
>
> My friend got it to 60 mpg with some very skilful and cautious driving
> away from motorways. .
--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk
Peter Johnson
May 14, 2022, 8:47:54 AM5/14/22
to
In March I drove from Woking to Leicester in a Prius. Before leaving,
the Satnav said the distance was 118 miles and the trip computer
estimated the range available to be also 118 miles.
Reaching the M1 I tucked in behind a sequence of HGVs and made the
journey at 60-65mph. Reached home with an estimated 5 miles range
still available.
the Satnav said the distance was 118 miles and the trip computer
estimated the range available to be also 118 miles.
Reaching the M1 I tucked in behind a sequence of HGVs and made the
journey at 60-65mph. Reached home with an estimated 5 miles range
still available.
alan_m
May 14, 2022, 8:48:19 AM5/14/22
to
On 14/05/2022 12:29, NY wrote:
> It's possible that the car used for the record had a less powerful
> engine (if that makes it more efficient) and I couldn't find any mention
> of whether the drivers had a lower self-imposed maximum speed to use
> less fuel. Maybe they only did each leg of the journey on a day that the
> wind was predominantly behind them ;-)
>
Or all unnecessary weight removed from the vehicle. No spare wheel, no
> It's possible that the car used for the record had a less powerful
> engine (if that makes it more efficient) and I couldn't find any mention
> of whether the drivers had a lower self-imposed maximum speed to use
> less fuel. Maybe they only did each leg of the journey on a day that the
> wind was predominantly behind them ;-)
>
luggage, no back seat etc.
alan_m
May 14, 2022, 9:17:36 AM5/14/22
to
On 14/05/2022 13:56, Jethro_uk wrote:
> You can tell how much of this climate "emergency" is bollocks from the
> fact that a rigidly enforced 65mph limit on motorways would save the UK
> quite a bit in fuel consumption. (Although not as much as not travelling
> at all).
I guess that a lot of people who think they are doing 70mph are actually
doing 63 to 65mph because most speedometers read 10% high.
Risk of accident wise, boredom on a long motorway journey is possibly a
higher risk than speed.
> You can tell how much of this climate "emergency" is bollocks from the
> fact that a rigidly enforced 65mph limit on motorways would save the UK
> quite a bit in fuel consumption. (Although not as much as not travelling
> at all).
I guess that a lot of people who think they are doing 70mph are actually
doing 63 to 65mph because most speedometers read 10% high.
Risk of accident wise, boredom on a long motorway journey is possibly a
higher risk than speed.
Martin Brown
May 14, 2022, 9:22:33 AM5/14/22
to
On 14/05/2022 10:20, Scott wrote:
since the drag is proportional to the square of the speed that the air
is going past your car. If you have the wind behind you then you
actually get less drag than in still air and into a headwind more.
to Perth = k(V-v)^2
from Perth = k(V+v)^2
--
Regards,
Martin Brown
williamwright
May 14, 2022, 9:43:19 AM5/14/22
to
£30's worth in.
Bill
NY
May 14, 2022, 10:00:38 AM5/14/22
to
"alan_m" <ju...@admac.myzen.co.uk> wrote in message
news:je9mof...@mid.individual.net...
the weight of fuel. 60 litres of diesel weighs about 50 kg which is about
half a person (OK, half a fairly heavy person like wot I am).
My grandpa had lived through fuel rationing in the war and had been taught
how to conserve fuel for the times when he was making an authorised journey.
It's ironic that his technique of slipping into neutral as he was slowing
down (which he still did to the day he stopped driving shortly before he
died in 1999) would actually be counterproductive with a modern
computer-controlled engine. I've proved it with the instantaneous
fuel-consumption menu on my car: pressing the clutch and keeping the engine
idling uses a measurable amount of fuel (which displays as around about 150
mpg) whereas lifting off the throttle and staying in gear (ie clutch not
pressed) uses a mythical 999 mpg. That's because the computer can cut the
fuel *totally* if the motion of the car on overrun will keep the engine
turning, whereas with the car in neutral (or clutch pressed) a token amount
of fuel is needed to keep the engine ticking over.
news:je9mof...@mid.individual.net...
> On 14/05/2022 12:29, NY wrote:
>
>> It's possible that the car used for the record had a less powerful engine
>> (if that makes it more efficient) and I couldn't find any mention of
>> whether the drivers had a lower self-imposed maximum speed to use less
>> fuel. Maybe they only did each leg of the journey on a day that the wind
>> was predominantly behind them ;-)
>
> Or all unnecessary weight removed from the vehicle. No spare wheel, no
> luggage, no back seat etc.
And maybe only put in a small amount of fuel and keep filling up, to reduce
>
>> It's possible that the car used for the record had a less powerful engine
>> (if that makes it more efficient) and I couldn't find any mention of
>> whether the drivers had a lower self-imposed maximum speed to use less
>> fuel. Maybe they only did each leg of the journey on a day that the wind
>> was predominantly behind them ;-)
>
> Or all unnecessary weight removed from the vehicle. No spare wheel, no
> luggage, no back seat etc.
the weight of fuel. 60 litres of diesel weighs about 50 kg which is about
half a person (OK, half a fairly heavy person like wot I am).
My grandpa had lived through fuel rationing in the war and had been taught
how to conserve fuel for the times when he was making an authorised journey.
It's ironic that his technique of slipping into neutral as he was slowing
down (which he still did to the day he stopped driving shortly before he
died in 1999) would actually be counterproductive with a modern
computer-controlled engine. I've proved it with the instantaneous
fuel-consumption menu on my car: pressing the clutch and keeping the engine
idling uses a measurable amount of fuel (which displays as around about 150
mpg) whereas lifting off the throttle and staying in gear (ie clutch not
pressed) uses a mythical 999 mpg. That's because the computer can cut the
fuel *totally* if the motion of the car on overrun will keep the engine
turning, whereas with the car in neutral (or clutch pressed) a token amount
of fuel is needed to keep the engine ticking over.
Scott
May 14, 2022, 10:10:17 AM5/14/22
to
advance of the stop and coast to save fuel but when I did the Advanced
Driving course, I was told the opposite (in gear at all times when
moving).
Jim Stewart ...
May 14, 2022, 10:23:32 AM5/14/22
to
On 14/05/2022 10:20, Scott wrote:
NY
May 14, 2022, 10:30:21 AM5/14/22
to
"Tim Streater" <timst...@greenbee.net> wrote in message
news:je9ojk...@mid.individual.net...
> manage to get 2 litres more in, doing that.
I tend to let the pump cutoff, try again, cutoff - and regard that as
"full".
But I'm well aware that there is quite a lot of variation in the cutoff
points of different pumps. I once did three consecutive tankfulls, filling
up at the same pump each time (at my local garage) and the consumption
figures were more consistent than for other tankfuls which had been filled
at a variety of pumps/garages. That suggests that the variation in driving
conditions from one tankful to the next can sometimes be less than the
variation in cutoff from one pump to another - which surprised me. I did
have a reading which was very suspect: dramatically better mpg on one
tankful followed by dramatically worse for the next tankful which makes me
think that one pump cutoff way before my tank was full.
But in general, a lot of driving on country lanes, slowing down for lots of
bends and then accelerating back to a typical straight-line speed in
between, will use more fuel than a constant 70 on a motorway, which in turn
will use more than a fairly constant 50-60 on a free-running A road. Town
driving - lots of short journeys, lots of stop/start at T junctions and
traffic lights, uses dramatically more.
news:je9ojk...@mid.individual.net...
> On 14 May 2022 at 12:29:05 BST, "NY" <m...@privacy.invalid> wrote:
>
>> But the best I've averaged on a tankful of fuel is about 60 mpg - and
>> that may
>> partly have been due to random filling differences (different pumps cut
>> out at
>> different points).
>
> Just pull the nozzle out a bit and continue to fill - carefully. I usually
>
>> But the best I've averaged on a tankful of fuel is about 60 mpg - and
>> that may
>> partly have been due to random filling differences (different pumps cut
>> out at
>> different points).
>
> manage to get 2 litres more in, doing that.
I tend to let the pump cutoff, try again, cutoff - and regard that as
"full".
But I'm well aware that there is quite a lot of variation in the cutoff
points of different pumps. I once did three consecutive tankfulls, filling
up at the same pump each time (at my local garage) and the consumption
figures were more consistent than for other tankfuls which had been filled
at a variety of pumps/garages. That suggests that the variation in driving
conditions from one tankful to the next can sometimes be less than the
variation in cutoff from one pump to another - which surprised me. I did
have a reading which was very suspect: dramatically better mpg on one
tankful followed by dramatically worse for the next tankful which makes me
think that one pump cutoff way before my tank was full.
But in general, a lot of driving on country lanes, slowing down for lots of
bends and then accelerating back to a typical straight-line speed in
between, will use more fuel than a constant 70 on a motorway, which in turn
will use more than a fairly constant 50-60 on a free-running A road. Town
driving - lots of short journeys, lots of stop/start at T junctions and
traffic lights, uses dramatically more.
Jeff Gaines
May 14, 2022, 10:35:55 AM5/14/22
to
On 14/05/2022 in message <je9pvi...@mid.individual.net> williamwright
wrote:
Absolutely :-)
Manufacturers are helping as well. When I bought my car the tank held £35
of petrol, they must have changed the tank at the last service as it now
holds £65 worth!
wrote:
Manufacturers are helping as well. When I bought my car the tank held £35
of petrol, they must have changed the tank at the last service as it now
holds £65 worth!
Fredxx
May 14, 2022, 11:10:08 AM5/14/22
to
http://drømstørre.dk/wp-content/wind/miller/windpower%20web/en/tour/wres/enrspeed.htm
Your engine power will be (wind speed)^4
Of course for petrol cars part throttle economy will be poor.
Harry Bloomfield Esq
May 14, 2022, 1:38:25 PM5/14/22
to
Clive Arthur has brought this to us :
against the breeze.
> Much the same happened to me on a longer trip of 260 miles which I'd done a
> few times. Yes, I'm pretty sure it's the wind that makes the difference.
..and me, I beat 60mpg going east but that declined to 50 going west
> few times. Yes, I'm pretty sure it's the wind that makes the difference.
against the breeze.
Andrew
May 14, 2022, 2:38:09 PM5/14/22
to
On 14/05/2022 13:48, alan_m wrote:
> On 14/05/2022 12:29, NY wrote:
>
>> It's possible that the car used for the record had a less powerful
>> engine (if that makes it more efficient) and I couldn't find any
>> mention of whether the drivers had a lower self-imposed maximum speed
>> to use less fuel. Maybe they only did each leg of the journey on a day
>> that the wind was predominantly behind them ;-)
>>
>
> Or all unnecessary weight removed from the vehicle. No spare wheel, no
> luggage, no back seat etc.
>
>
And car manufacturers used to tape over all the body seams and door
> On 14/05/2022 12:29, NY wrote:
>
>> It's possible that the car used for the record had a less powerful
>> engine (if that makes it more efficient) and I couldn't find any
>> mention of whether the drivers had a lower self-imposed maximum speed
>> to use less fuel. Maybe they only did each leg of the journey on a day
>> that the wind was predominantly behind them ;-)
>>
>
> Or all unnecessary weight removed from the vehicle. No spare wheel, no
> luggage, no back seat etc.
>
>
aperatures the past to get the best fuel consumption.
alan_m
May 14, 2022, 3:40:53 PM5/14/22
to
On 14/05/2022 19:18, Jethro_uk wrote:
> climate catastrophe (c).
If there is going to be a climate catastrophe then just enjoy the high
speeds and excessive consumption of fossil fuel while we can.
> On Sat, 14 May 2022 14:17:30 +0100, alan_m wrote:
>
>> On 14/05/2022 13:56, Jethro_uk wrote:
>>
>>> You can tell how much of this climate "emergency" is bollocks from the
>>> fact that a rigidly enforced 65mph limit on motorways would save the UK
>>> quite a bit in fuel consumption. (Although not as much as not
>>> travelling at all).
>>
>> I guess that a lot of people who think they are doing 70mph are actually
>> doing 63 to 65mph because most speedometers read 10% high.
>>
>> Risk of accident wise, boredom on a long motorway journey is possibly a
>> higher risk than speed.
>
> All of which pales into insignificance when compared to the oncoming
>
>> On 14/05/2022 13:56, Jethro_uk wrote:
>>
>>> You can tell how much of this climate "emergency" is bollocks from the
>>> fact that a rigidly enforced 65mph limit on motorways would save the UK
>>> quite a bit in fuel consumption. (Although not as much as not
>>> travelling at all).
>>
>> I guess that a lot of people who think they are doing 70mph are actually
>> doing 63 to 65mph because most speedometers read 10% high.
>>
>> Risk of accident wise, boredom on a long motorway journey is possibly a
>> higher risk than speed.
>
> climate catastrophe (c).
If there is going to be a climate catastrophe then just enjoy the high
speeds and excessive consumption of fossil fuel while we can.
mm0fmf
May 14, 2022, 3:44:54 PM5/14/22
to
over 30mph. It also removes a few hundred bhp from under your right foot
and changes the revs when it changes gear. The saving on fuel is very
noticeable. As is the fact it becomes a slow car. I also note that I get
a better mpg at a constant 75mph than 70mph when using cruise on the
motorway. Slowing down more, such as 60mph on cruise on the A9 and the
mpg goes up of course. Just this bizarre 70<>75 issue.
mm0fmf
May 14, 2022, 3:46:03 PM5/14/22
to
lacksey
May 14, 2022, 3:48:51 PM5/14/22
to
On Sat, 14 May 2022 19:20:53 +1000, Scott <newsg...@gefion.myzen.co.uk>
wrote:
> I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
> the drive computer at the start. On the way north, I was running late
> and driving a bit faster than usual. I also got caught in a traffic
> jam on the M8. When I arrived I checked the display and it showed
> 52.5 mpg. l reset the drive computer before returning. I drove more
> slowly on the way home, without the traffic jam, and got 48.8 mpg.
>
> Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
>
> How can this be? I thought slowing down saved fuel. The only
> explanation I can think of is that I may have been driving into the
> wind on the way south. Could this account for the variation?
Yep, easily. And in lower gears for longer in the traffic jam.
> I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
> the drive computer at the start. On the way north, I was running late
> and driving a bit faster than usual. I also got caught in a traffic
> jam on the M8. When I arrived I checked the display and it showed
> 52.5 mpg. l reset the drive computer before returning. I drove more
> slowly on the way home, without the traffic jam, and got 48.8 mpg.
>
> Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
>
> How can this be? I thought slowing down saved fuel. The only
> explanation I can think of is that I may have been driving into the
> wind on the way south. Could this account for the variation?
Rod Speed
May 14, 2022, 4:23:37 PM5/14/22
to
alan_m <ju...@admac.myzen.co.uk> wrote
> Risk of accident wise, boredom on a long motorwayjourney is possibly a
> higher risk than speed.
Not just possibly, absolutely certainly. The accident risk is
vastly lower with proper modern fully divided motorways.
essentially because they are much more forgiving even
if you do something really stupid like come off the lane.
> Risk of accident wise, boredom on a long motorwayjourney is possibly a
> higher risk than speed.
Not just possibly, absolutely certainly. The accident risk is
vastly lower with proper modern fully divided motorways.
essentially because they are much more forgiving even
if you do something really stupid like come off the lane.
NY
May 14, 2022, 4:36:35 PM5/14/22
to
"Rod Speed" <rod.sp...@gmail.com> wrote in message
news:op.1l6dk...@pvr2.lan...
I've heard it said (and it may or may not be true - I don't have statistics)
that the accident rate on German autobahns (Autobahnen?) which have no speed
limit is lower than those which have a limit of around 70 mph (in km/hr)
because on an unlimited autobahn, drivers are constantly checking their door
mirror for a fast car coming up on their left before they change lanes,
whereas if they "know" that nothing (in theory!) will be going much faster
than them on a speed-limited autobahn, they indicate-and-go without checking
as thoroughly. Not sure whether it's true or bullshit.
news:op.1l6dk...@pvr2.lan...
that the accident rate on German autobahns (Autobahnen?) which have no speed
limit is lower than those which have a limit of around 70 mph (in km/hr)
because on an unlimited autobahn, drivers are constantly checking their door
mirror for a fast car coming up on their left before they change lanes,
whereas if they "know" that nothing (in theory!) will be going much faster
than them on a speed-limited autobahn, they indicate-and-go without checking
as thoroughly. Not sure whether it's true or bullshit.
SH
May 14, 2022, 4:38:33 PM5/14/22
to
after espensive things, Mercedes, Pearl, Ruby, Porsche etc....
This time next year , new borns will be named Diesel, Petrol, Gas and
Electric!
SH
May 14, 2022, 4:39:46 PM5/14/22
to
On 14/05/2022 14:43, williamwright wrote:
be hoping its enough to get you to pump 6!
Rod Speed
May 14, 2022, 4:45:43 PM5/14/22
to
NY <m...@privacy.invalid> wrote
> Rod Speed <rod.sp...@gmail.com> wrote
Problem with that claim is that likely the ones with no speed
limit are also much safer to drive on and that is why the ones
with a speed limit have a speed limit.
> Rod Speed <rod.sp...@gmail.com> wrote
limit are also much safer to drive on and that is why the ones
with a speed limit have a speed limit.
Rod Speed
May 14, 2022, 4:53:49 PM5/14/22
to
SH <i.lov...@spam.com> wrote
> mm0fmf wrote
>> williamwright wrote
>>> The increases in fuel costs don't affect me because I always put
>>> exactly £30's worth in.
popularity lists.
Certain a mate of mine and his wife did that, but the first one is called
Austin
after the ancient Austin ute that he got from his grand dad and restored.
Not sure why the next girl was called Porsche, likely because it was
one of the few well known car brands that can be used for girls.
Their dog has the official name, not a nickname, of fleabag, quite
literally.
> This time next year , new borns will be named Diesel, Petrol, Gas and
> Electric!
Diesel has been around for quite a while as a kids name, not very common
tho.
One Jap tried to call his kid Devil but the poh faced bureaucrats wouldn't
let him.
> mm0fmf wrote
>> williamwright wrote
>>> The increases in fuel costs don't affect me because I always put
>>> exactly £30's worth in.
>> ROTLF. Thank you Bill.
> Has anyone noticed that new mums and dads often call their new borns
> after espensive things, Mercedes, Pearl, Ruby, Porsche etc....
Not convinced that it is often, I do look at the annual kids names
> Has anyone noticed that new mums and dads often call their new borns
> after espensive things, Mercedes, Pearl, Ruby, Porsche etc....
popularity lists.
Certain a mate of mine and his wife did that, but the first one is called
Austin
after the ancient Austin ute that he got from his grand dad and restored.
Not sure why the next girl was called Porsche, likely because it was
one of the few well known car brands that can be used for girls.
Their dog has the official name, not a nickname, of fleabag, quite
literally.
> This time next year , new borns will be named Diesel, Petrol, Gas and
> Electric!
tho.
One Jap tried to call his kid Devil but the poh faced bureaucrats wouldn't
let him.
NY
May 14, 2022, 5:03:29 PM5/14/22
to
"Rod Speed" <rod.sp...@gmail.com> wrote in message
news:op.1l6el...@pvr2.lan...
traffic, and which are straighter and have fewer / safer junctions.
Do German autobahns have the US characteristic of a dedicated exit lane
before a junction and a dedicated entry lane after it to allow leaving
traffic to slow down below the speed of traffic that is not leaving, and to
allow entering traffic plenty of space to get up to the speed of the traffic
that they are joining? (*) As long as the dedicated exit lane is clearly
marked (which wasn't always the case on "motorways" that I drove on in
Massachusetts in the late 90s) to avoid the problem of last minute lane
changes, the exit/entry lane is a good idea. Do German autobahns allow
overtaking on either side, or are they as strict as we are about only
overtake on the left (right in the UK)? That was one thing that I found
*very* unnerving on US motorways - traffic passing you on your passenger
side.
(*) I am always on the look out after I pass a junction for vehicles which
thing that it is acceptable to move from the slip road to Lane 1 when they
are doing only 30 mph and I'm coming up behind them at 70. If there is a gap
in Lane 2, I usually move from Lane 1 to 2 just before the entry slip to
allow entering traffic to use Lane 1 as a continuation of an acceleration
lane - especially if the entering traffic has to go *uphill* (roundabout
below the motorway) rather than downhill (roundabout above the motorway)
because the former means that low power-to-weight vehicles might struggle to
reach motorway speed by the end of the slip road.
Scott
May 14, 2022, 5:25:39 PM5/14/22
to
Paul
May 14, 2022, 5:30:53 PM5/14/22
to
On 5/14/2022 9:19 AM, Tim Streater wrote:
> On 14 May 2022 at 12:29:05 BST, "NY" <m...@privacy.invalid> wrote:
>
>> But the best I've averaged on a tankful of fuel is about 60 mpg - and that may
>> partly have been due to random filling differences (different pumps cut out at
>> different points).
>
> Just pull the nozzle out a bit and continue to fill - carefully. I usually
> manage to get 2 litres more in, doing that.
>
I would not recommend doing that.
> On 14 May 2022 at 12:29:05 BST, "NY" <m...@privacy.invalid> wrote:
>
>> But the best I've averaged on a tankful of fuel is about 60 mpg - and that may
>> partly have been due to random filling differences (different pumps cut out at
>> different points).
>
> Just pull the nozzle out a bit and continue to fill - carefully. I usually
> manage to get 2 litres more in, doing that.
>
Your car can have a charcoal filter, for reducing VOC from the
fuel system. It runs off vacuum, and anything pulled through
the canister is burned in the engine.
The car is designed to cut off fuel fill, in concert with
the station nozzle device, to a safe level. when it stops filling,
you're done. You'd not supposed to fill it all the way up to the
little spring-loaded door :-) This is not the old days. I don't
think my first car had all that fancy junk on it.
https://www.cars.com/articles/what-happens-when-you-fill-up-with-too-much-gas-442051/
And I nearly lost that canister on the road, because the
car company put a less-than-adequate bracket on it, to
hold it to the car, and the bracket rusted off.
Paul
Scott
May 14, 2022, 5:31:38 PM5/14/22
to
round and fifth gear would be the most efficient.
Rod Speed
May 14, 2022, 5:46:56 PM5/14/22
to
> As long as the dedicated exit lane is clearly marked (which wasn't
> always the case on "motorways" that I drove on in Massachusetts in the
> late 90s) to avoid the problem of last minute lane changes, the
> exit/entry lane is a good idea.
> Do German autobahns allow overtaking on either side,
> or are they as strict as we are about only overtake on the left (right
> in the UK)?
https://en.wikipedia.org/wiki/Autobahn#Traffic_laws_and_enforcement
> That was one thing that I found *very* unnerving on US motorways -
> traffic passing you on your passenger side.
here with multilane major roads inside citys, not just motorways.
> (*) I am always on the look out after I pass a junction for vehicles
> which thing that it is acceptable to move from the slip road to Lane 1
> when they are doing only 30 mph and I'm coming up behind them at 70.
road.
Scott
May 14, 2022, 5:53:27 PM5/14/22
to
On 14 May 2022 21:49:46 GMT, Tim Streater <timst...@greenbee.net>
wrote:
>On 14 May 2022 at 22:30:48 BST, Paul <nos...@needed.invalid> wrote:
>
>> On 5/14/2022 9:19 AM, Tim Streater wrote:
>>> On 14 May 2022 at 12:29:05 BST, "NY" <m...@privacy.invalid> wrote:
>>>
>>>> But the best I've averaged on a tankful of fuel is about 60 mpg - and that may
>>>> partly have been due to random filling differences (different pumps cut out at
>>>> different points).
>>>
>>> Just pull the nozzle out a bit and continue to fill - carefully. I usually
>>> manage to get 2 litres more in, doing that.
>>
>> I would not recommend doing that.
>>
>> Your car can have a charcoal filter, for reducing VOC from the
>> fuel system. It runs off vacuum, and anything pulled through
>> the canister is burned in the engine.
>>
>> The car is designed to cut off fuel fill, in concert with
>> the station nozzle device, to a safe level. when it stops filling,
>> you're done. You'd not supposed to fill it all the way up to the
>> little spring-loaded door :-) This is not the old days. I don't
>> think my first car had all that fancy junk on it.
>>
>> https://www.cars.com/articles/what-happens-when-you-fill-up-with-too-much-gas-442051/
>
>I've never had a problem doing this. No lights come on and I don't get told
>off by the nice chaps at Toyota when I take the car in for service once a
>year.
>
>And pump nozzles here don't have a "large rubber collar or accordion-like tube
>on the pump handle that covers the opening of your filler neck while you’re
>filling your tank".
I was taught it depended on temperature and whether you were
immediately going to drive something like five miles.
wrote:
>On 14 May 2022 at 22:30:48 BST, Paul <nos...@needed.invalid> wrote:
>
>> On 5/14/2022 9:19 AM, Tim Streater wrote:
>>> On 14 May 2022 at 12:29:05 BST, "NY" <m...@privacy.invalid> wrote:
>>>
>>>> But the best I've averaged on a tankful of fuel is about 60 mpg - and that may
>>>> partly have been due to random filling differences (different pumps cut out at
>>>> different points).
>>>
>>> Just pull the nozzle out a bit and continue to fill - carefully. I usually
>>> manage to get 2 litres more in, doing that.
>>
>> I would not recommend doing that.
>>
>> Your car can have a charcoal filter, for reducing VOC from the
>> fuel system. It runs off vacuum, and anything pulled through
>> the canister is burned in the engine.
>>
>> The car is designed to cut off fuel fill, in concert with
>> the station nozzle device, to a safe level. when it stops filling,
>> you're done. You'd not supposed to fill it all the way up to the
>> little spring-loaded door :-) This is not the old days. I don't
>> think my first car had all that fancy junk on it.
>>
>> https://www.cars.com/articles/what-happens-when-you-fill-up-with-too-much-gas-442051/
>
>off by the nice chaps at Toyota when I take the car in for service once a
>year.
>
>And pump nozzles here don't have a "large rubber collar or accordion-like tube
>on the pump handle that covers the opening of your filler neck while you’re
>filling your tank".
I was taught it depended on temperature and whether you were
immediately going to drive something like five miles.
Peeler
May 14, 2022, 5:53:55 PM5/14/22
to
On Sun, 15 May 2022 06:53:40 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:
<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
Bod addressing senile Rodent Speed:
"Rod, you have a sick twisted mind. I suggest you stop your mindless
and totally irresponsible talk. Your mouth could get you into a lot of
trouble."
MID: <gfbb94...@mid.individual.net>
Speed, the auto-contradicting senile sociopath, blabbered, again:
<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
Bod addressing senile Rodent Speed:
"Rod, you have a sick twisted mind. I suggest you stop your mindless
and totally irresponsible talk. Your mouth could get you into a lot of
trouble."
MID: <gfbb94...@mid.individual.net>
lacksey
May 14, 2022, 5:54:44 PM5/14/22
to
On Sun, 15 May 2022 07:31:33 +1000, Scott <newsg...@gefion.myzen.co.uk>
wrote:
Not in a traffic jam.
wrote:
Peeler
May 14, 2022, 5:54:45 PM5/14/22
to
On Sun, 15 May 2022 06:23:02 +1000, cantankerous trolling geezer Rodent
"This is just a hunch, but I'm betting you're kinda an argumentative
asshole.
MID: <ev1p6ml7ywd5$.d...@sqwertz.com>
Speed, the auto-contradicting senile sociopath, blabbered, again:
<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
Sqwertz to Rodent Speed:
<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
"This is just a hunch, but I'm betting you're kinda an argumentative
asshole.
MID: <ev1p6ml7ywd5$.d...@sqwertz.com>
Peeler
May 14, 2022, 5:55:07 PM5/14/22
to
On Sun, 15 May 2022 06:45:34 +1000, cantankerous trolling geezer Rodent
"Do you practice arguing with yourself in an empty room?"
MID: <g4ihla...@mid.individual.net>
Speed, the auto-contradicting senile sociopath, blabbered, again:
<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
Bod addressing abnormal senile quarreller Rodent Speed:
<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
"Do you practice arguing with yourself in an empty room?"
MID: <g4ihla...@mid.individual.net>
Peeler
May 14, 2022, 5:55:45 PM5/14/22
to
On Sun, 15 May 2022 05:48:43 +1000, lackseycantankerous trolling geezer
"This is like having a conversation with someone with brain damage."
MID: <ps10v9$uo2$1...@gioia.aioe.org>
Rodent Speed, the auto-contradicting senile sociopath, blabbered, again:
<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
MrTu...@down.the.farm about senile Rodent Speed:
<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
"This is like having a conversation with someone with brain damage."
MID: <ps10v9$uo2$1...@gioia.aioe.org>
The Natural Philosopher
May 14, 2022, 6:04:16 PM5/14/22
to
On 14/05/2022 13:56, Jethro_uk wrote:
> fact that a rigidly enforced 65mph limit on motorways would save the UK
> quite a bit in fuel consumption.
That's not a fact. In fact rigid speed limits end up with people braking
> fact that a rigidly enforced 65mph limit on motorways would save the UK
> quite a bit in fuel consumption.
and accelerating all the time to keep to them. Biggest fuel burn for me
is roads with humps in them and chicanes that are one way. Every time I
slow or stop the car it takes a cupful of diesel to get it moving again
idling in traffic queues also burns a shitload
--
"When a true genius appears in the world, you may know him by this sign,
that the dunces are all in confederacy against him."
Jonathan Swift.
The Natural Philosopher
May 14, 2022, 6:05:03 PM5/14/22
to
On 14/05/2022 19:18, Jethro_uk wrote:
> On Sat, 14 May 2022 14:17:30 +0100, alan_m wrote:
>
> On Sat, 14 May 2022 14:17:30 +0100, alan_m wrote:
>
>> On 14/05/2022 13:56, Jethro_uk wrote:
>>
>>
>>> You can tell how much of this climate "emergency" is bollocks from the
>>> fact that a rigidly enforced 65mph limit on motorways would save the UK
>>> quite a bit in fuel consumption. (Although not as much as not
>>> travelling at all).
>>
>> I guess that a lot of people who think they are doing 70mph are actually
>> doing 63 to 65mph because most speedometers read 10% high.
>>
>>> travelling at all).
>>
>> I guess that a lot of people who think they are doing 70mph are actually
>> doing 63 to 65mph because most speedometers read 10% high.
>>
>> Risk of accident wise, boredom on a long motorway journey is possibly a
>> higher risk than speed.
>
>> higher risk than speed.
>
> All of which pales into insignificance when compared to the oncoming
> climate catastrophe (c).
LOL!
> climate catastrophe (c).
--
Any fool can believe in principles - and most of them do!
The Natural Philosopher
May 14, 2022, 6:07:10 PM5/14/22
to
I made it a rule never to travel much faster than 20mph more than the
people I was overtaking. Hurtlng past an old codger doing 60 mph and
120mph is fraught...
The Natural Philosopher
May 14, 2022, 6:11:17 PM5/14/22
to
efficiency, profile drag and rolling resistance. My current car is
actually best at around 50-70mph in top gear.
Stopping ruins the fuel economy.
--
“Ideas are inherently conservative. They yield not to the attack of
other ideas but to the massive onslaught of circumstance"
- John K Galbraith
Peeler
May 14, 2022, 6:23:06 PM5/14/22
to
On Sun, 15 May 2022 07:46:48 +1000, cantankerous trolling geezer Rodent
cretin's pathological trolling:
https://www.pcreview.co.uk/threads/rod-speed-faq.2973853/
Speed, the auto-contradicting senile sociopath, blabbered, again:
<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
Website (from 2007) dedicated to the 87-year-old senile Australian
<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
cretin's pathological trolling:
https://www.pcreview.co.uk/threads/rod-speed-faq.2973853/
Peeler
May 14, 2022, 6:23:36 PM5/14/22
to
On Sun, 15 May 2022 07:54:36 +1000, lacksey, better known as cantankerous
trolling senile geezer Rodent Speed, wrote:
<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
Norman Wells addressing trolling senile Rodent:
trolling senile geezer Rodent Speed, wrote:
<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
"Ah, the voice of scum speaks."
MID: <g4t0jt...@mid.individual.net>
ARW
May 15, 2022, 2:00:04 AM5/15/22
to
On 14/05/2022 10:20, Scott wrote:
> I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
> the drive computer at the start. On the way north, I was running late
> and driving a bit faster than usual. I also got caught in a traffic
> jam on the M8. When I arrived I checked the display and it showed
> 52.5 mpg. l reset the drive computer before returning. I drove more
> slowly on the way home, without the traffic jam, and got 48.8 mpg.
>
> Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
>
> How can this be? I thought slowing down saved fuel. The only
> explanation I can think of is that I may have been driving into the
> wind on the way south. Could this account for the variation?
I always get more MPG on the way to the office than on the way back in
> I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
> the drive computer at the start. On the way north, I was running late
> and driving a bit faster than usual. I also got caught in a traffic
> jam on the M8. When I arrived I checked the display and it showed
> 52.5 mpg. l reset the drive computer before returning. I drove more
> slowly on the way home, without the traffic jam, and got 48.8 mpg.
>
> Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
>
> How can this be? I thought slowing down saved fuel. The only
> explanation I can think of is that I may have been driving into the
> wind on the way south. Could this account for the variation?
both the van or the car. 41 mile round trip.
I have decided it's the roundabouts (17 of the bastards), other traffic
and a heavy right foot. In a morning most of the roundabouts are usually
clear so I do not have to stop. On the way home I have to come to a stop
at the most of the roundabouts. It's the acceleration from standstill
that causes the loss of MPG.
ARW
May 15, 2022, 2:10:50 AM5/15/22
to
that is 3 times a week
ARW
May 15, 2022, 2:18:08 AM5/15/22
to
On 14/05/2022 13:56, Jethro_uk wrote:
> produces the most efficient output - usually c. 3000-3500 rpm for petrol.
>
> I once saved 25% on a 100 mile journey by doing 55 instead of 75.
75MPH? I have CC set to 90MPH.
> You can tell how much of this climate "emergency" is bollocks from the
> fact that a rigidly enforced 65mph limit on motorways would save the UK
> quite a bit in fuel consumption. (Although not as much as not travelling
> at all).
Have a go on the M1 from junction 34 to 32. 60MPH for air quality -
applies to all vehicles including electric ones. And when there was 25
miles of 50MPH road works further south I got brilliant MPG going to
Watford.
> On Sat, 14 May 2022 10:20:53 +0100, Scott wrote:
>
>> I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
>> the drive computer at the start. On the way north, I was running late
>> and driving a bit faster than usual. I also got caught in a traffic jam
>> on the M8. When I arrived I checked the display and it showed 52.5 mpg.
>> l reset the drive computer before returning. I drove more slowly on
>> the way home, without the traffic jam, and got 48.8 mpg.
>>
>> Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
>>
>> How can this be? I thought slowing down saved fuel. The only
>> explanation I can think of is that I may have been driving into the wind
>> on the way south. Could this account for the variation?
>
> Depends on loads of things, not least the envelope where the engine
>
>> I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
>> the drive computer at the start. On the way north, I was running late
>> and driving a bit faster than usual. I also got caught in a traffic jam
>> on the M8. When I arrived I checked the display and it showed 52.5 mpg.
>> l reset the drive computer before returning. I drove more slowly on
>> the way home, without the traffic jam, and got 48.8 mpg.
>>
>> Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
>>
>> How can this be? I thought slowing down saved fuel. The only
>> explanation I can think of is that I may have been driving into the wind
>> on the way south. Could this account for the variation?
>
> produces the most efficient output - usually c. 3000-3500 rpm for petrol.
>
> I once saved 25% on a 100 mile journey by doing 55 instead of 75.
75MPH? I have CC set to 90MPH.
> You can tell how much of this climate "emergency" is bollocks from the
> fact that a rigidly enforced 65mph limit on motorways would save the UK
> quite a bit in fuel consumption. (Although not as much as not travelling
> at all).
applies to all vehicles including electric ones. And when there was 25
miles of 50MPH road works further south I got brilliant MPG going to
Watford.
Scott
May 15, 2022, 5:15:56 AM5/15/22
to
will take you more miles travelling in first and second gear with lots
of stop-start than it would driving at a steady speed on a motorway?
lacksey
May 15, 2022, 6:15:23 AM5/15/22
to
On Sun, 15 May 2022 19:15:49 +1000, Scott <newsg...@gefion.myzen.co.uk>
No, that staying in fifth gear doesn't work in a traffic jam.
Mike Rogers
May 15, 2022, 6:47:43 AM5/15/22
to
On 14/05/2022 10:20, Scott wrote:
> I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
> the drive computer at the start. On the way north, I was running late
> and driving a bit faster than usual.
What 55MPH instead of your usual 35MPH?
> I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
> the drive computer at the start. On the way north, I was running late
> and driving a bit faster than usual.
I also got caught in a traffic
> jam on the M8. When I arrived I checked the display and it showed
> 52.5 mpg. l reset the drive computer before returning. I drove more
> slowly on the way home,
Back to your normal 35MPH
> jam on the M8. When I arrived I checked the display and it showed
> 52.5 mpg. l reset the drive computer before returning. I drove more
> slowly on the way home,
without the traffic jam, and got 48.8 mpg.
>
> Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
>
> How can this be?
55MPH is allegedly the most economical speed.
>
> Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
>
> How can this be?
Mike
Scott
May 15, 2022, 7:20:26 AM5/15/22
to
I said I got better mpg travelling north despite a traffic jam, and
attributed this to the wind. You responded that driving in lower
gears for longer in the traffic jam may also have been a contributory
factor [to the improved mpg]. I simply queried the suggestion that a
traffic jam would improve fuel economy as I cannot see how this can be
correct. .
Scott
May 15, 2022, 7:27:13 AM5/15/22
to
On Sun, 15 May 2022 11:47:34 +0100, Mike Rogers
<mi...@mattishall.org.uk> wrote:
>On 14/05/2022 10:20, Scott wrote:
>> I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
>> the drive computer at the start. On the way north, I was running late
>> and driving a bit faster than usual.
>
>What 55MPH instead of your usual 35MPH?
No mate - efficient vehicle:
<mi...@mattishall.org.uk> wrote:
>On 14/05/2022 10:20, Scott wrote:
>> I drove to Perth yesterday (Scotland not Australia), 62 miles. I set
>> the drive computer at the start. On the way north, I was running late
>> and driving a bit faster than usual.
>
>What 55MPH instead of your usual 35MPH?
https://www.honestjohn.co.uk/realmpg/nissan/micra-2003
>I also got caught in a traffic
>> jam on the M8. When I arrived I checked the display and it showed
>> 52.5 mpg. l reset the drive computer before returning. I drove more
>> slowly on the way home,
>Back to your normal 35MPH
>without the traffic jam, and got 48.8 mpg.
>>
>> Nissan Micra 1.2. Petrol. Manual gearbox, five gears.
>>
>> How can this be?
>55MPH is allegedly the most economical speed.
answered, thanks.
charles
May 15, 2022, 7:54:33 AM5/15/22
to
In article <ppo18h9taosh7s6hk...@4ax.com>,
it will depend on the aerodynamics of the vehicle. I find my Enyaq is best
at 62mph.
--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle
at 62mph.
--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle
Scott
May 15, 2022, 8:24:06 AM5/15/22
to
On Sun, 15 May 2022 12:54:13 +0100, charles <cha...@candehope.me.uk>
wrote:
Airspeed rather than groundspeed I assume :-)
wrote:
The Natural Philosopher
May 15, 2022, 8:47:59 AM5/15/22
to
On 15/05/2022 06:59, ARW wrote:
> It's the acceleration from standstill that causes the loss of MPG.
In anything with weight and a large engine that is absolutely the case.
> It's the acceleration from standstill that causes the loss of MPG.
I monitor fuel consumption on a per tank basis. Two stops to let people
past on a narrow country road will take a 10 mile trip from 35mpg down
to 30mpg.
--
Karl Marx said religion is the opium of the people.
But Marxism is the crack cocaine.
The Natural Philosopher
May 15, 2022, 8:53:18 AM5/15/22
to
On 15/05/2022 11:47, Mike Rogers wrote:
> 55MPH is allegedly the most economical speed.
There is no single 'most economical speed' For a Boeing 737 its around
> 55MPH is allegedly the most economical speed.
450mph
For my car its around 65mph. For a bicycle its somewhere around 12mph.
It is a mixture of three things on a wheeled vehicle - the least energy
needed is when rolling resistance matches air resistance. The smaller
the tyre width and the lighter the vehicle the slower that will be...but
that may not be where the engine is most efficient, that too has its
optimum speed for best efficiency.
Tim+
May 15, 2022, 10:57:59 AM5/15/22
to
Personally, I find this highly doubtful.
Given the way that wind resistance rises with the square of speed (in
general) it seems incredibly improbably that 55 mph should be more
economical than 40 mph say.
Far more likely is that the OP had a weak headwind (say just 10mph) one way
and a tailwind the other way.
Whilst a 10mph wind might not be noticed it effectively makes a 20mph
difference in wind on a return journey.
I suspect the 55 mph figure has been taken out of context. More likely
it’s a figure quoted and being significantly more economical than 70 mph
but still allows reasonable progress to be made in real world traffic.
Tim
--
Please don't feed the trolls
Given the way that wind resistance rises with the square of speed (in
general) it seems incredibly improbably that 55 mph should be more
economical than 40 mph say.
Far more likely is that the OP had a weak headwind (say just 10mph) one way
and a tailwind the other way.
Whilst a 10mph wind might not be noticed it effectively makes a 20mph
difference in wind on a return journey.
I suspect the 55 mph figure has been taken out of context. More likely
it’s a figure quoted and being significantly more economical than 70 mph
but still allows reasonable progress to be made in real world traffic.
Tim
--
Please don't feed the trolls
Richard
May 15, 2022, 11:04:00 AM5/15/22
to
Peeler
May 15, 2022, 11:04:34 AM5/15/22
to
On Sun, 15 May 2022 20:15:14 +1000, lacksey, better known as cantankerous
trolling senile geezer Rodent Speed, wrote:
<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
<FLUSH the abnormal trolling senile cretin's latest trollshit unread>
--
ARW
May 15, 2022, 11:42:18 AM5/15/22
to
On 15/05/2022 13:47, The Natural Philosopher wrote:
> On 15/05/2022 06:59, ARW wrote:
>> It's the acceleration from standstill that causes the loss of MPG.
> In anything with weight and a large engine that is absolutely the case.
> I monitor fuel consumption on a per tank basis. Two stops to let people
> past on a narrow country road will take a 10 mile trip from 35mpg down
> to 30mpg.
>
>
That's about the MPG difference I get in the van when stopping at the
> On 15/05/2022 06:59, ARW wrote:
>> It's the acceleration from standstill that causes the loss of MPG.
> In anything with weight and a large engine that is absolutely the case.
> I monitor fuel consumption on a per tank basis. Two stops to let people
> past on a narrow country road will take a 10 mile trip from 35mpg down
> to 30mpg.
>
>
roundabouts and not stopping.
Although in lockdown my MPG dropped as I was able to drive as fast as I
wanted:-)
NY
May 15, 2022, 3:59:05 PM5/15/22
to
"Tim Streater" <timst...@greenbee.net> wrote in message
news:jeam41...@mid.individual.net...
> On 14 May 2022 at 22:03:19 BST, "NY" <m...@privacy.invalid> wrote:
>
>> Do German autobahns have the US characteristic of a dedicated exit lane
>> before a junction and a dedicated entry lane after it to allow leaving
>> traffic to slow down below the speed of traffic that is not leaving, and
>> to
>> allow entering traffic plenty of space to get up to the speed of the
>> traffic
>> that they are joining? (*) As long as the dedicated exit lane is clearly
>> marked (which wasn't always the case on "motorways" that I drove on in
>> Massachusetts in the late 90s) to avoid the problem of last minute lane
>> changes, the exit/entry lane is a good idea.
>
> The bad thing about US freeways is that you have two off-roads at each
> actual
> exit, depending on which way you want to go (left or right) at the top.
> They
> do this instead of having a roundabout at the top as we do. Two bad
> consequences of this:
>
> 1) If you're not sure which one you need and take the wrong one, you're
> then
> going in the wrong direction on the road you've exited onto, and the lack
> of
> roundabouts make it hard to turn around. Especially if they also prevent
> U-turns at a number of subsequent junctions.
>
> 2) Traffic exiting on one of those exits is crossing traffic entering at
> one
> of the two entrances. This is quite dangerous as traffic getting on the
> freeway is accelerating while traffic getting off is trying to slow down.
I don't remember seeing any junctions with two exits for the two directions.
Maybe I was lucky - this was in rural Massachusetts (towns about 30 miles
north of Boston) with one long journey from there to/from Cape Cod. That was
when I was visiting my sister and her family who were living near Boston for
a few years.
Americans really don't like roundabouts. I only remember one, and that's
where the coastal road and the road onto the Cape Code peninsular cross. It
was a six-way roundabout (called a "rotary") and I worked out what to expect
from the advance sign, so I got into the left lane, went round
anti-clockwise (which felt slightly odd) and came off. All a bit of a
non-event: what I was very used to, except a perfect mirror-image. When I
stopped at a cafe a few miles later, the car behind me also stopped, and the
driver actually came over and shook my hand: he'd been behind me and had
been impressed with the fact that I seemed so confident. Then he heard my
voice and he said "Gee, you're not even American. You're not even used to
driving on the right." I though for a moment he was going to bow and kiss my
feet ;-)
> I found US roads to be poorly signed and badly designed (the 4-way stop is
> another POS). Their aim appears to be to ensure that you can't drive from
> A to
> B without becoming an administrative criminal (and thus paying a fine).
I only encountered one 4-way-stop junction while I was there, and that was
near the airport. Thankfully I was the only car at the junction, so I didn't
have to play the "what order did everyone arrive in" game. The 4WS junction
is badly flawed for two reasons: it uses time (order of arrival) rather than
position (give way to traffic coming from the left - in the US); and it
forces all traffic to stop dead, rather than allowing traffic to keep
rolling - maybe even at full speed limit - if it can see that there is no
traffic coming from the conflicting directions. I prefer the UK arrangement
for cross-roads, where one direction is designated the major road with
absolute priority over traffic coming at 90 degrees which must give way -
nice and simple, and not based on "I was here before you".
One peculiarity that I noticed with US signing (leaving aside distances
quoted in absurdly large number of feet, instead of "100 yards" or "2 1/2
miles") was the fact that at a T junction, the direction signs give
directions with respect to the way the road was oriented at that point. So
you'd be travelling generally northwards, but if the road locally turned
east-west, or even back on itself and there was a junction, you were
signposted East and West, or even North and South but reversed. Here, the
local orientation of the road is immaterial: the road will say "N" or "S"
based on whether the destination is north or south of where you are.
I also had to endure the most stupid, idiotic, nonsensical, imbecilic road
atlas I've ever seen. Here in the UK, all the pages of a road atlas are to
the same scale, in the same cartographic style, and are ordered
consecutively west to east for one row, and then west to east for the next
maps further north, and so on. If you are going east-west then you only need
to turn forwards or backwards by one page. This map book (my sister and her
family bought it when they first arrived, and then realised that it was
crap) had double-page spreads organised by alphabetically by "town"
(effectively the built-up part of the town and the surrounding countryside
that came under that town council's jurisdiction), and each map would be at
a different scale according to the boundaries of the "town". As you were
about to leave one map, you had to turn to a completely different part of
the book (not to a consecutive page) and then try to work out where the
overlap was when the spacing of roads was different because of the change of
scale, and maybe there was even detail on one map that wasn't present on the
other. This was in the days before satnavs - late 1990s. And the
continuation arrows at the edge of a map said "continued on Ipswich" (so you
had turn pages until you found it), and not even "continued on page 17".
That map book was an object lesson in how to make a book as un-user-friendly
as possible - it probably won first prize in the Bastard Map Book From Hell
contest ;-)
Very often, where a minor road joined a major road, there was no
give-way/yield/stop line. If the junction is at a right angle, you can infer
where you have to stop from the edges of the kerbs (sorry, curbs), but where
the junction of your minor road is on a bend of a major road, it's very
difficult to judge where the imaginary *curved* line is.
There were some very good things. Drivers were a lot more tolerant of car
that took their time in getting away from lights (partly because there is no
red+amber phase to give you time to put the car in gear and take the
handbrake off), and, both in small towns and in central Boston, they were
far more willing to stop to let pedestrians cross, even at places other that
designated pedestrian crossings. I once stopped near a shop front (ie not on
the kerb) and looked across at the building opposite, before planning to
carry on walking along the street. Immediately traffic in both directions
stopped, thinking I was about to cross. Their zebra crossings had me baffled
for a while: there was a sign "PED XING" which was a random set of letters
until it dawned on me "PEDestrian (Cross)-ing".
The main problem on rural roads was if you got behind a school bus:
essentially you were stuck behind it for eternity because unless the road
was clear you couldn't overtake it while it was moving, and when it stopped
it flashed its "DO NOT OVERTAKE" lights, and the driver didn't even wait for
a few seconds after the last child had got clear, to allow traffic stuck
behind to overtake before he set off again.
The one thing about American cars which was indescribably dangerous was the
combined side/indicator and tail/indicator lights, where two front lights
were replaced by a steady white light on one side and a flashing one on the
other, likewise for steady/flashing red lights at the back. My sister was
taking my parents out for a drive and was stopped in the middle of the road,
indicating left to turn into a side road. And her car was hit from behind by
a driver who didn't see the flashing tail light, and who assumed that
because she didn't have her brake lights on (because she was stopped on the
handbrake until she could see a gap) she was setting off. At least we have
indicators which are a different colour, even if modern car design
co-locates those indicators with the bright brake lights or with the
headlights. Ever since then, I've got into the habit of flashing my brake
lights a couple of times when I'm stopped in the middle of the road if I see
a car coming up behind me, or even breaking my unwritten rule of never
keeping my brake lights on (to avoid dazzling that car behind) when I'm
stopped, in the special case when I'm stopped in the middle of the major
road waiting to turn.
news:jeam41...@mid.individual.net...
> On 14 May 2022 at 22:03:19 BST, "NY" <m...@privacy.invalid> wrote:
>
>> Do German autobahns have the US characteristic of a dedicated exit lane
>> before a junction and a dedicated entry lane after it to allow leaving
>> traffic to slow down below the speed of traffic that is not leaving, and
>> to
>> allow entering traffic plenty of space to get up to the speed of the
>> traffic
>> that they are joining? (*) As long as the dedicated exit lane is clearly
>> marked (which wasn't always the case on "motorways" that I drove on in
>> Massachusetts in the late 90s) to avoid the problem of last minute lane
>> changes, the exit/entry lane is a good idea.
>
> The bad thing about US freeways is that you have two off-roads at each
> actual
> exit, depending on which way you want to go (left or right) at the top.
> They
> do this instead of having a roundabout at the top as we do. Two bad
> consequences of this:
>
> 1) If you're not sure which one you need and take the wrong one, you're
> then
> going in the wrong direction on the road you've exited onto, and the lack
> of
> roundabouts make it hard to turn around. Especially if they also prevent
> U-turns at a number of subsequent junctions.
>
> 2) Traffic exiting on one of those exits is crossing traffic entering at
> one
> of the two entrances. This is quite dangerous as traffic getting on the
> freeway is accelerating while traffic getting off is trying to slow down.
I don't remember seeing any junctions with two exits for the two directions.
Maybe I was lucky - this was in rural Massachusetts (towns about 30 miles
north of Boston) with one long journey from there to/from Cape Cod. That was
when I was visiting my sister and her family who were living near Boston for
a few years.
Americans really don't like roundabouts. I only remember one, and that's
where the coastal road and the road onto the Cape Code peninsular cross. It
was a six-way roundabout (called a "rotary") and I worked out what to expect
from the advance sign, so I got into the left lane, went round
anti-clockwise (which felt slightly odd) and came off. All a bit of a
non-event: what I was very used to, except a perfect mirror-image. When I
stopped at a cafe a few miles later, the car behind me also stopped, and the
driver actually came over and shook my hand: he'd been behind me and had
been impressed with the fact that I seemed so confident. Then he heard my
voice and he said "Gee, you're not even American. You're not even used to
driving on the right." I though for a moment he was going to bow and kiss my
feet ;-)
> I found US roads to be poorly signed and badly designed (the 4-way stop is
> another POS). Their aim appears to be to ensure that you can't drive from
> A to
> B without becoming an administrative criminal (and thus paying a fine).
I only encountered one 4-way-stop junction while I was there, and that was
near the airport. Thankfully I was the only car at the junction, so I didn't
have to play the "what order did everyone arrive in" game. The 4WS junction
is badly flawed for two reasons: it uses time (order of arrival) rather than
position (give way to traffic coming from the left - in the US); and it
forces all traffic to stop dead, rather than allowing traffic to keep
rolling - maybe even at full speed limit - if it can see that there is no
traffic coming from the conflicting directions. I prefer the UK arrangement
for cross-roads, where one direction is designated the major road with
absolute priority over traffic coming at 90 degrees which must give way -
nice and simple, and not based on "I was here before you".
One peculiarity that I noticed with US signing (leaving aside distances
quoted in absurdly large number of feet, instead of "100 yards" or "2 1/2
miles") was the fact that at a T junction, the direction signs give
directions with respect to the way the road was oriented at that point. So
you'd be travelling generally northwards, but if the road locally turned
east-west, or even back on itself and there was a junction, you were
signposted East and West, or even North and South but reversed. Here, the
local orientation of the road is immaterial: the road will say "N" or "S"
based on whether the destination is north or south of where you are.
I also had to endure the most stupid, idiotic, nonsensical, imbecilic road
atlas I've ever seen. Here in the UK, all the pages of a road atlas are to
the same scale, in the same cartographic style, and are ordered
consecutively west to east for one row, and then west to east for the next
maps further north, and so on. If you are going east-west then you only need
to turn forwards or backwards by one page. This map book (my sister and her
family bought it when they first arrived, and then realised that it was
crap) had double-page spreads organised by alphabetically by "town"
(effectively the built-up part of the town and the surrounding countryside
that came under that town council's jurisdiction), and each map would be at
a different scale according to the boundaries of the "town". As you were
about to leave one map, you had to turn to a completely different part of
the book (not to a consecutive page) and then try to work out where the
overlap was when the spacing of roads was different because of the change of
scale, and maybe there was even detail on one map that wasn't present on the
other. This was in the days before satnavs - late 1990s. And the
continuation arrows at the edge of a map said "continued on Ipswich" (so you
had turn pages until you found it), and not even "continued on page 17".
That map book was an object lesson in how to make a book as un-user-friendly
as possible - it probably won first prize in the Bastard Map Book From Hell
contest ;-)
Very often, where a minor road joined a major road, there was no
give-way/yield/stop line. If the junction is at a right angle, you can infer
where you have to stop from the edges of the kerbs (sorry, curbs), but where
the junction of your minor road is on a bend of a major road, it's very
difficult to judge where the imaginary *curved* line is.
There were some very good things. Drivers were a lot more tolerant of car
that took their time in getting away from lights (partly because there is no
red+amber phase to give you time to put the car in gear and take the
handbrake off), and, both in small towns and in central Boston, they were
far more willing to stop to let pedestrians cross, even at places other that
designated pedestrian crossings. I once stopped near a shop front (ie not on
the kerb) and looked across at the building opposite, before planning to
carry on walking along the street. Immediately traffic in both directions
stopped, thinking I was about to cross. Their zebra crossings had me baffled
for a while: there was a sign "PED XING" which was a random set of letters
until it dawned on me "PEDestrian (Cross)-ing".
The main problem on rural roads was if you got behind a school bus:
essentially you were stuck behind it for eternity because unless the road
was clear you couldn't overtake it while it was moving, and when it stopped
it flashed its "DO NOT OVERTAKE" lights, and the driver didn't even wait for
a few seconds after the last child had got clear, to allow traffic stuck
behind to overtake before he set off again.
The one thing about American cars which was indescribably dangerous was the
combined side/indicator and tail/indicator lights, where two front lights
were replaced by a steady white light on one side and a flashing one on the
other, likewise for steady/flashing red lights at the back. My sister was
taking my parents out for a drive and was stopped in the middle of the road,
indicating left to turn into a side road. And her car was hit from behind by
a driver who didn't see the flashing tail light, and who assumed that
because she didn't have her brake lights on (because she was stopped on the
handbrake until she could see a gap) she was setting off. At least we have
indicators which are a different colour, even if modern car design
co-locates those indicators with the bright brake lights or with the
headlights. Ever since then, I've got into the habit of flashing my brake
lights a couple of times when I'm stopped in the middle of the road if I see
a car coming up behind me, or even breaking my unwritten rule of never
keeping my brake lights on (to avoid dazzling that car behind) when I'm
stopped, in the special case when I'm stopped in the middle of the major
road waiting to turn.
NY
May 15, 2022, 4:26:40 PM5/15/22
to
"Tim+" <tim.d...@gmail.com> wrote in message
news:38662732.674319089.1248...@news.individual.net...
top gear. So 40 mph in sixth may be more efficient that 35 mph in fifth. I
imagine there are a lot of other factors as well: it may well be that petrol
engines and diesel engines behave differently as regards efficiency when
it's a toss-up between driving with a slightly higher engine speed but less
load on the engine, versus a slightly lower engine speed in the next gear up
which makes the engine work harder.
As far as I can tell, my HDi diesel car gives better results with the engine
running more slowly and *slightly* labouring in a just-too-high gear, as
opposed to with the engine running more freely but more quickly in a
just-too-low gear. But I think my previous petrol cars were the other way
round. As far as I could tell.
The problem with determining which is better is that the instantaneous fuel
consumption figures on a trip computer are often *too* instantaneous so they
vary all over the place from second to second, whereas if there was an
averaged update every 2-5 seconds, you could compare the two cases (slightly
too low a gear versus slightly too high a gear) without lots of random
"clutter" in the readings.
news:38662732.674319089.1248...@news.individual.net...
> Mike Rogers <mi...@mattishall.org.uk> wrote:
>
>> 55MPH is allegedly the most economical speed.
>
> Personally, I find this highly doubtful.
>
> Given the way that wind resistance rises with the square of speed (in
> general) it seems incredibly improbably that 55 mph should be more
> economical than 40 mph say.
The most efficient speed is probably the slowest at which you can drive in
>
>> 55MPH is allegedly the most economical speed.
>
> Personally, I find this highly doubtful.
>
> Given the way that wind resistance rises with the square of speed (in
> general) it seems incredibly improbably that 55 mph should be more
> economical than 40 mph say.
top gear. So 40 mph in sixth may be more efficient that 35 mph in fifth. I
imagine there are a lot of other factors as well: it may well be that petrol
engines and diesel engines behave differently as regards efficiency when
it's a toss-up between driving with a slightly higher engine speed but less
load on the engine, versus a slightly lower engine speed in the next gear up
which makes the engine work harder.
As far as I can tell, my HDi diesel car gives better results with the engine
running more slowly and *slightly* labouring in a just-too-high gear, as
opposed to with the engine running more freely but more quickly in a
just-too-low gear. But I think my previous petrol cars were the other way
round. As far as I could tell.
The problem with determining which is better is that the instantaneous fuel
consumption figures on a trip computer are often *too* instantaneous so they
vary all over the place from second to second, whereas if there was an
averaged update every 2-5 seconds, you could compare the two cases (slightly
too low a gear versus slightly too high a gear) without lots of random
"clutter" in the readings.
Tim+
May 15, 2022, 5:00:01 PM5/15/22
to
Scott <newsg...@gefion.myzen.co.uk> wrote:
> On Sat, 14 May 2022 15:00:20 +0100, "NY" <m...@privacy.invalid> wrote:
>
>> "alan_m" <ju...@admac.myzen.co.uk> wrote in message
>> news:je9mof...@mid.individual.net...
>>> On 14/05/2022 12:29, NY wrote:
>>>
>>>> It's possible that the car used for the record had a less powerful engine
>>>> (if that makes it more efficient) and I couldn't find any mention of
>>>> whether the drivers had a lower self-imposed maximum speed to use less
>>>> fuel. Maybe they only did each leg of the journey on a day that the wind
>>>> was predominantly behind them ;-)
>>>
>>> Or all unnecessary weight removed from the vehicle. No spare wheel, no
>>> luggage, no back seat etc.
>>
>> And maybe only put in a small amount of fuel and keep filling up, to reduce
>> the weight of fuel. 60 litres of diesel weighs about 50 kg which is about
>> half a person (OK, half a fairly heavy person like wot I am).
>>
>> My grandpa had lived through fuel rationing in the war and had been taught
>> how to conserve fuel for the times when he was making an authorised journey.
>> It's ironic that his technique of slipping into neutral as he was slowing
>> down (which he still did to the day he stopped driving shortly before he
>> died in 1999) would actually be counterproductive with a modern
>> computer-controlled engine. I've proved it with the instantaneous
>> fuel-consumption menu on my car: pressing the clutch and keeping the engine
>> idling uses a measurable amount of fuel (which displays as around about 150
>> mpg) whereas lifting off the throttle and staying in gear (ie clutch not
>> pressed) uses a mythical 999 mpg. That's because the computer can cut the
>> fuel *totally* if the motion of the car on overrun will keep the engine
>> turning, whereas with the car in neutral (or clutch pressed) a token amount
>> of fuel is needed to keep the engine ticking over.
>
> Interesting. I never knew that. I was taught to move into neutral in
> advance of the stop and coast to save fuel but when I did the Advanced
> Driving course, I was told the opposite (in gear at all times when
> moving).
>
But this ignores the “in gear drag” which means the loss of an amount of
kinetic energy. If the drag is costing you more in wasted fuel than an
idling engine, you’re better off coasting.
Working out exactly at what speeds and circumstances this applies isn’t
straightforward.
> On Sat, 14 May 2022 15:00:20 +0100, "NY" <m...@privacy.invalid> wrote:
>
>> "alan_m" <ju...@admac.myzen.co.uk> wrote in message
>> news:je9mof...@mid.individual.net...
>>> On 14/05/2022 12:29, NY wrote:
>>>
>>>> It's possible that the car used for the record had a less powerful engine
>>>> (if that makes it more efficient) and I couldn't find any mention of
>>>> whether the drivers had a lower self-imposed maximum speed to use less
>>>> fuel. Maybe they only did each leg of the journey on a day that the wind
>>>> was predominantly behind them ;-)
>>>
>>> Or all unnecessary weight removed from the vehicle. No spare wheel, no
>>> luggage, no back seat etc.
>>
>> And maybe only put in a small amount of fuel and keep filling up, to reduce
>> the weight of fuel. 60 litres of diesel weighs about 50 kg which is about
>> half a person (OK, half a fairly heavy person like wot I am).
>>
>> My grandpa had lived through fuel rationing in the war and had been taught
>> how to conserve fuel for the times when he was making an authorised journey.
>> It's ironic that his technique of slipping into neutral as he was slowing
>> down (which he still did to the day he stopped driving shortly before he
>> died in 1999) would actually be counterproductive with a modern
>> computer-controlled engine. I've proved it with the instantaneous
>> fuel-consumption menu on my car: pressing the clutch and keeping the engine
>> idling uses a measurable amount of fuel (which displays as around about 150
>> mpg) whereas lifting off the throttle and staying in gear (ie clutch not
>> pressed) uses a mythical 999 mpg. That's because the computer can cut the
>> fuel *totally* if the motion of the car on overrun will keep the engine
>> turning, whereas with the car in neutral (or clutch pressed) a token amount
>> of fuel is needed to keep the engine ticking over.
>
> Interesting. I never knew that. I was taught to move into neutral in
> advance of the stop and coast to save fuel but when I did the Advanced
> Driving course, I was told the opposite (in gear at all times when
> moving).
>
But this ignores the “in gear drag” which means the loss of an amount of
kinetic energy. If the drag is costing you more in wasted fuel than an
idling engine, you’re better off coasting.
Working out exactly at what speeds and circumstances this applies isn’t
straightforward.
Tim+
May 15, 2022, 5:00:01 PM5/15/22
to
NY <m...@privacy.invalid> wrote:
> "Tim+" <tim.d...@gmail.com> wrote in message
> news:38662732.674319089.1248...@news.individual.net...
>> Mike Rogers <mi...@mattishall.org.uk> wrote:
>>
>>> 55MPH is allegedly the most economical speed.
>>
>> Personally, I find this highly doubtful.
>>
>> Given the way that wind resistance rises with the square of speed (in
>> general) it seems incredibly improbably that 55 mph should be more
>> economical than 40 mph say.
>
> The most efficient speed is probably the slowest at which you can drive in
> top gear.
Gears? An abomination forced upon a motor with terrible power
> "Tim+" <tim.d...@gmail.com> wrote in message
> news:38662732.674319089.1248...@news.individual.net...
>> Mike Rogers <mi...@mattishall.org.uk> wrote:
>>
>>> 55MPH is allegedly the most economical speed.
>>
>> Personally, I find this highly doubtful.
>>
>> Given the way that wind resistance rises with the square of speed (in
>> general) it seems incredibly improbably that 55 mph should be more
>> economical than 40 mph say.
>
> The most efficient speed is probably the slowest at which you can drive in
> top gear.
characteristics! ;-)
In reality, I’d bet that doing 40mph in a lower gear would still be more
economical than 55 in top just because of wind resistance.
Tim+
May 15, 2022, 5:00:01 PM5/15/22
to
Harry Bloomfield Esq <a...@harrym1byt.plus.com> wrote:
> Clive Arthur has brought this to us :
>> Much the same happened to me on a longer trip of 260 miles which I'd done a
>> few times. Yes, I'm pretty sure it's the wind that makes the difference.
>
> ..and me, I beat 60mpg going east but that declined to 50 going west
> against the breeze.
>
I used 50kWhr this weekend to do 260 miles (130 north, 130 south). Not sure
what that is in mpg…
> Clive Arthur has brought this to us :
>> Much the same happened to me on a longer trip of 260 miles which I'd done a
>> few times. Yes, I'm pretty sure it's the wind that makes the difference.
>
> ..and me, I beat 60mpg going east but that declined to 50 going west
> against the breeze.
>
I used 50kWhr this weekend to do 260 miles (130 north, 130 south). Not sure
what that is in mpg…
Scott
May 15, 2022, 5:35:15 PM5/15/22
to
Australia.
Animal
May 15, 2022, 5:48:02 PM5/15/22
to
On Saturday, 14 May 2022 at 21:38:33 UTC+1, SH wrote:
> Has anyone noticed that new mums and dads often call their new borns
> after espensive things, Mercedes, Pearl, Ruby, Porsche etc....
>
> This time next year , new borns will be named Diesel, Petrol, Gas and
> Electric!
In Russia there are people called Tractor & Voucher. In Thailand, Tuktuk is a popularish name. In the Philippines there's Bongbong & Dingdong.
> On 14/05/2022 20:45, mm0fmf wrote:
> > On 14/05/2022 14:43, williamwright wrote:
> >> On 14/05/2022 13:47, Peter Johnson wrote:
> >>> In March I drove from Woking to Leicester in a Prius. Before leaving,
> >>> the Satnav said the distance was 118 miles and the trip computer
> >>> estimated the range available to be also 118 miles.
> >>> Reaching the M1 I tucked in behind a sequence of HGVs and made the
> >>> journey at 60-65mph. Reached home with an estimated 5 miles range
> >>> still available.
> >>
> >> The increases in fuel costs don't affect me because I always put
> >> exactly £30's worth in.
> >>
> >> Bill
> >
> > ROTLF. Thank you Bill.
> > On 14/05/2022 14:43, williamwright wrote:
> >> On 14/05/2022 13:47, Peter Johnson wrote:
> >>> In March I drove from Woking to Leicester in a Prius. Before leaving,
> >>> the Satnav said the distance was 118 miles and the trip computer
> >>> estimated the range available to be also 118 miles.
> >>> Reaching the M1 I tucked in behind a sequence of HGVs and made the
> >>> journey at 60-65mph. Reached home with an estimated 5 miles range
> >>> still available.
> >>
> >> The increases in fuel costs don't affect me because I always put
> >> exactly £30's worth in.
> >>
> >> Bill
> >
> Has anyone noticed that new mums and dads often call their new borns
> after espensive things, Mercedes, Pearl, Ruby, Porsche etc....
>
> This time next year , new borns will be named Diesel, Petrol, Gas and
> Electric!
In Russia there are people called Tractor & Voucher. In Thailand, Tuktuk is a popularish name. In the Philippines there's Bongbong & Dingdong.
Animal
May 15, 2022, 5:55:24 PM5/15/22
to
Fredxx
May 16, 2022, 1:40:44 AM5/16/22
to
On 15/05/2022 22:27, Tim Streater wrote:
> A litre contains about 10kWh, so that's 5 litres. A gallon is 4.55 litres. So
> there you are.
Last I looked 85% of electricity was generated with fossil fuels, and
given generation and the grid transmission efficiency is nominally 30%,
you need to multiply that accordingly. I would suggest 16 litres. Or
73mpg. A modern diesel should be able to manage that with less PMs too.
> there you are.
Last I looked 85% of electricity was generated with fossil fuels, and
given generation and the grid transmission efficiency is nominally 30%,
you need to multiply that accordingly. I would suggest 16 litres. Or
73mpg. A modern diesel should be able to manage that with less PMs too.
Richard
May 16, 2022, 3:34:47 AM5/16/22
to
Andy Burns
May 16, 2022, 6:03:36 AM5/16/22
to
mm0fmf wrote:
> My car in eco mode (8 speed auto) drops in to neutral when you lift off over 30mph.
Mine does that, and when going downhill, will also stop the engine.
> My car in eco mode (8 speed auto) drops in to neutral when you lift off over 30mph.
Mine does that, and when going downhill, will also stop the engine.
Andy Burns
May 16, 2022, 6:19:26 AM5/16/22
to
Scott wrote:
> Richard
Every time you see a new nym, ask youself "Is this Rod?" a couple of sentences
is all it takes to decide that it is, in 90% of cases.
> Richard
>
>> you're discussing with rod speed.
>
> I did not realise that. The laws of physics are different in
> Australia.
How often do new users stumble upon usenet?
>> you're discussing with rod speed.
>
> I did not realise that. The laws of physics are different in
> Australia.
Every time you see a new nym, ask youself "Is this Rod?" a couple of sentences
is all it takes to decide that it is, in 90% of cases.
Clive Arthur
May 16, 2022, 6:24:42 AM5/16/22
to
[And 2000 Calories is 2.3kWh meaning your body averages something under
100W.]
--
Cheers
Clive
Scott
May 16, 2022, 6:27:01 AM5/16/22
to
On Mon, 16 May 2022 11:19:20 +0100, Andy Burns <use...@andyburns.uk>
wrote:
Could it not equally be his mate Commander Kinsey / James Wilkinson?
wrote:
Richard
May 16, 2022, 6:38:37 AM5/16/22
to
On 16/05/2022 11:24, Clive Arthur wrote:
> On 16/05/2022 08:34, Richard wrote:
>> On 15/05/2022 21:59, Tim+ wrote:
>>> Harry Bloomfield Esq <a...@harrym1byt.plus.com> wrote:
>>>> Clive Arthur has brought this to us :
>>>>> Much the same happened to me on a longer trip of 260 miles which
>>>>> I'd done a
>>>>> few times. Yes, I'm pretty sure it's the wind that makes the
>>>>> difference.
>>>>
>>>> ..and me, I beat 60mpg going east but that declined to 50 going west
>>>> against the breeze.
>>>>
>>>
>>> I used 50kWhr this weekend to do 260 miles (130 north, 130 south).
>>> Not sure
>>> what that is in mpg…
>>
>> 42 bananas.
>
> Nearer 410 bananas. 1kWh is 860 Calories, a banana is 105 Calories.
Ah, but what size banana?
> On 16/05/2022 08:34, Richard wrote:
>> On 15/05/2022 21:59, Tim+ wrote:
>>> Harry Bloomfield Esq <a...@harrym1byt.plus.com> wrote:
>>>> Clive Arthur has brought this to us :
>>>>> Much the same happened to me on a longer trip of 260 miles which
>>>>> I'd done a
>>>>> few times. Yes, I'm pretty sure it's the wind that makes the
>>>>> difference.
>>>>
>>>> ..and me, I beat 60mpg going east but that declined to 50 going west
>>>> against the breeze.
>>>>
>>>
>>> I used 50kWhr this weekend to do 260 miles (130 north, 130 south).
>>> Not sure
>>> what that is in mpg…
>>
>> 42 bananas.
>
> Nearer 410 bananas. 1kWh is 860 Calories, a banana is 105 Calories.
>
> [And 2000 Calories is 2.3kWh meaning your body averages something under
> 100W.]
the 100W you are guessing at.
alan_m
May 16, 2022, 6:41:28 AM5/16/22
to
On 15/05/2022 22:35, Scott wrote:
>
> I did not realise that. The laws of physics are different in
> Australia.
On the other side of the world where everything is upside down gravity
>
> I did not realise that. The laws of physics are different in
> Australia.
barely holds things down to the earth's surface so the rolling
resistance of a car is a lot less.
--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk
The Natural Philosopher
May 16, 2022, 6:49:39 AM5/16/22
to
does engine braking which seems to use less fuel..making a seamless
shift with a torque converter seems to use huge amounts of fuel
--
Renewable energy: Expensive solutions that don't work to a problem that
doesn't exist instituted by self legalising protection rackets that
don't protect, masquerading as public servants who don't serve the public.
Richard
May 16, 2022, 6:54:12 AM5/16/22
to
NY
May 16, 2022, 7:03:54 AM5/16/22
to
"Richard" <smit...@btinternet.com.invalid> wrote in message
news:t5t9j7$1uk1$1...@gioia.aioe.org...
news:t5t9j7$1uk1$1...@gioia.aioe.org...
>>>> I used 50kWhr this weekend to do 260 miles (130 north, 130 south). Not
>>>> sure
>>>> what that is in mpg…
>>>
>>> 42 bananas.
>>
>> Nearer 410 bananas. 1kWh is 860 Calories, a banana is 105 Calories.
>
> Ah, but what size banana?
And are they bent or straight bananas?
>>>> sure
>>>> what that is in mpg…
>>>
>>> 42 bananas.
>>
>> Nearer 410 bananas. 1kWh is 860 Calories, a banana is 105 Calories.
>
> Ah, but what size banana?
Richard
May 16, 2022, 7:25:12 AM5/16/22
to
NY
May 16, 2022, 7:33:41 AM5/16/22
to
"Richard" <smit...@btinternet.com.invalid> wrote in message
news:t5tcal$17d7$1...@gioia.aioe.org...
Anyone for a trans banana?
Richard
May 16, 2022, 8:17:34 AM5/16/22
to
On 16/05/2022 12:33, NY wrote:
> "Richard" <smit...@btinternet.com.invalid> wrote in message
> news:t5tcal$17d7$1...@gioia.aioe.org...
>> On 16/05/2022 12:03, NY wrote:
>>> "Richard" <smit...@btinternet.com.invalid> wrote in message
>>> news:t5t9j7$1uk1$1...@gioia.aioe.org...
>>>>>>> I used 50kWhr this weekend to do 260 miles (130 north, 130
>>>>>>> south). Not sure
>>>>>>> what that is in mpg…
>>>>>>
>>>>>> 42 bananas.
>>>>>
>>>>> Nearer 410 bananas. 1kWh is 860 Calories, a banana is 105 Calories.
>>>>
>>>> Ah, but what size banana?
>>>
>>> And are they bent or straight bananas?
>>
>> Orientation, or geometric?
>
> Good point. I was thinking of geometric, forgetting about orientation.
> Anyone for a trans banana?
Is that swallowed sideways?
> "Richard" <smit...@btinternet.com.invalid> wrote in message
> news:t5tcal$17d7$1...@gioia.aioe.org...
>> On 16/05/2022 12:03, NY wrote:
>>> "Richard" <smit...@btinternet.com.invalid> wrote in message
>>> news:t5t9j7$1uk1$1...@gioia.aioe.org...
>>>>>>> I used 50kWhr this weekend to do 260 miles (130 north, 130
>>>>>>> south). Not sure
>>>>>>> what that is in mpg…
>>>>>>
>>>>>> 42 bananas.
>>>>>
>>>>> Nearer 410 bananas. 1kWh is 860 Calories, a banana is 105 Calories.
>>>>
>>>> Ah, but what size banana?
>>>
>>> And are they bent or straight bananas?
>>
>> Orientation, or geometric?
>
> Good point. I was thinking of geometric, forgetting about orientation.
> Anyone for a trans banana?
The Natural Philosopher
May 16, 2022, 8:41:24 AM5/16/22
to
nearer 90%.
--
Truth welcomes investigation because truth knows investigation will lead
to converts. It is deception that uses all the other techniques.
Robin
May 16, 2022, 10:50:58 AM5/16/22
to
https://bananaprosthetics.com/pages/a-propos
--
Robin
reply-to address is (intended to be) valid
NY
May 16, 2022, 11:06:13 AM5/16/22
to
"Richard" <smit...@btinternet.com.invalid> wrote in message
news:t5tfcr$n3n$2...@gioia.aioe.org...
Richard
May 16, 2022, 2:10:12 PM5/16/22
to
Andrew
May 16, 2022, 2:35:21 PM5/16/22
to
On 16/05/2022 11:03, Andy Burns wrote:
sort of freewheel to prevent the engine from seizing, but also
meant no engine braking. I am old enough to remember the
"engage low gear" sign on long downhill gradients, but I haven't
seen one for ages. The long downhill going down into Bath when you
come from the M4 has an escape road at the bottom for errant HGV's
etc.
Footnote: Just realised that 'seized' breaks the "i before e
except after c" rule.
https://en.wikipedia.org/wiki/I_before_E_except_after_C
Andrew
May 16, 2022, 2:42:48 PM5/16/22
to
On 15/05/2022 21:59, Tim+ wrote:
£50 in petrol at 40mpg
Andrew
May 16, 2022, 2:44:43 PM5/16/22
to
On 16/05/2022 11:24, Clive Arthur wrote:
We need a pandemic. Blimey what happened ?.
Vir Campestris
May 16, 2022, 4:32:50 PM5/16/22
to
On 14/05/2022 13:56, Jethro_uk wrote:
> Depends on loads of things, not least the envelope where the engine
> produces the most efficient output - usually c. 3000-3500 rpm for petrol.
>
> I once saved 25% on a 100 mile journey by doing 55 instead of 75.
>
> You can tell how much of this climate "emergency" is bollocks from the
> fact that a rigidly enforced 65mph limit on motorways would save the UK
> quite a bit in fuel consumption. (Although not as much as not travelling
> at all).
Sadly peak torque, and probably peak engine efficiency in my car is at
~95MPH...
When we feel like being economical we take my wife's car. 1300 hatchback
with cruise control is better at motorway speeds than my 20yo sports
car. And gets 48MPG instead of 35.
(Off the motorway, OTOH...)
And I'll believe that fuel is too expensive when I stop seeing people
whizz past me when I'm on the (GPS checked) speed limit.
Andy
> Depends on loads of things, not least the envelope where the engine
> produces the most efficient output - usually c. 3000-3500 rpm for petrol.
>
> I once saved 25% on a 100 mile journey by doing 55 instead of 75.
>
> You can tell how much of this climate "emergency" is bollocks from the
> fact that a rigidly enforced 65mph limit on motorways would save the UK
> quite a bit in fuel consumption. (Although not as much as not travelling
> at all).
Sadly peak torque, and probably peak engine efficiency in my car is at
~95MPH...
When we feel like being economical we take my wife's car. 1300 hatchback
with cruise control is better at motorway speeds than my 20yo sports
car. And gets 48MPG instead of 35.
(Off the motorway, OTOH...)
And I'll believe that fuel is too expensive when I stop seeing people
whizz past me when I'm on the (GPS checked) speed limit.
Andy
Vir Campestris
May 16, 2022, 4:35:00 PM5/16/22
to
On 14/05/2022 16:10, Fredxx wrote:
> Shouldn't that be a cubic function of wind speed?
>
> http://drømstørre.dk/wp-content/wind/miller/windpower%20web/en/tour/wres/enrspeed.htm
>
>
> Your engine power will be (wind speed)^4
>
> Of course for petrol cars part throttle economy will be poor.
The power needed to push you through the air is directly proportional to
the power you can extract from the wind.
Both are cubic.
Andy
> Shouldn't that be a cubic function of wind speed?
>
> http://drømstørre.dk/wp-content/wind/miller/windpower%20web/en/tour/wres/enrspeed.htm
>
>
> Your engine power will be (wind speed)^4
>
> Of course for petrol cars part throttle economy will be poor.
The power needed to push you through the air is directly proportional to
the power you can extract from the wind.
Both are cubic.
Andy
Vir Campestris
May 16, 2022, 4:41:27 PM5/16/22
to
On 15/05/2022 13:53, The Natural Philosopher wrote:
> On 15/05/2022 11:47, Mike Rogers wrote:
>> 55MPH is allegedly the most economical speed.
> There is no single 'most economical speed' For a Boeing 737 its around
> 450mph
> For my car its around 65mph. For a bicycle its somewhere around 12mph.
> It is a mixture of three things on a wheeled vehicle - the least energy
> needed is when rolling resistance matches air resistance. The smaller
> the tyre width and the lighter the vehicle the slower that will be...but
> that may not be where the engine is most efficient, that too has its
> optimum speed for best efficiency.
>
Do you have a source for that? I suspect wheeled vehicles use less
energy the slower they go. Electrics (with no real engine losses) are
probably best at bicycle speed.
It's different for the Boeing; air friction of all types (skin, form) is
proportional to speed squared, but induced drag is proportional to the
reciprocal of speed. Usually best economy is when they are the same.
Climbing to thinner air helps a lot too of course.
Andy
> On 15/05/2022 11:47, Mike Rogers wrote:
>> 55MPH is allegedly the most economical speed.
> There is no single 'most economical speed' For a Boeing 737 its around
> 450mph
> For my car its around 65mph. For a bicycle its somewhere around 12mph.
> It is a mixture of three things on a wheeled vehicle - the least energy
> needed is when rolling resistance matches air resistance. The smaller
> the tyre width and the lighter the vehicle the slower that will be...but
> that may not be where the engine is most efficient, that too has its
> optimum speed for best efficiency.
>
Do you have a source for that? I suspect wheeled vehicles use less
energy the slower they go. Electrics (with no real engine losses) are
probably best at bicycle speed.
It's different for the Boeing; air friction of all types (skin, form) is
proportional to speed squared, but induced drag is proportional to the
reciprocal of speed. Usually best economy is when they are the same.
Climbing to thinner air helps a lot too of course.
Andy
Tim+
May 16, 2022, 5:12:03 PM5/16/22
to
Tim Streater <timst...@greenbee.net> wrote:
> On 16 May 2022 at 19:35:14 BST, Andrew <Andrew9...@mybtinternet.com>
>
Saab 93 and early 96.
Tim
--
Please don't feed the trolls
> On 16 May 2022 at 19:35:14 BST, Andrew <Andrew9...@mybtinternet.com>
> wrote:
>
>> On 16/05/2022 11:03, Andy Burns wrote:
>>> mm0fmf wrote:
>>>
>>>> My car in eco mode (8 speed auto) drops in to neutral when you lift
>>>> off over 30mph.
>>>
>>> Mine does that, and when going downhill, will also stop the engine.
>>
>> 2-stroke Saab 9x's did that decades ago because they had some
>> sort of freewheel to prevent the engine from seizing, but also
>> meant no engine braking.
>
> You talking about the Saab 99?
>
>> On 16/05/2022 11:03, Andy Burns wrote:
>>> mm0fmf wrote:
>>>
>>>> My car in eco mode (8 speed auto) drops in to neutral when you lift
>>>> off over 30mph.
>>>
>>> Mine does that, and when going downhill, will also stop the engine.
>>
>> 2-stroke Saab 9x's did that decades ago because they had some
>> sort of freewheel to prevent the engine from seizing, but also
>> meant no engine braking.
>
>
Saab 93 and early 96.
Tim
--
Please don't feed the trolls
Tim+
May 16, 2022, 5:15:53 PM5/16/22
to
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