Does freeway driving mileage go down with passengers in the car?
laura bush - VEHICULAR HOMICIDE
lot of accelerating. But in constant speed driving like on a freeway,
i would think the reduction is very slight.
Bill Bonde ('by a commodius vicus of recirculation')
So you also think that adding a trailer to a car doesn't affect highway
mileage much? At what point does it start to matter? And if putting a
few fat people in your car doesn't matter, then why does it matter if
you drive alone in your SUV, using the extra weight of passengers for
the extra features of the SUV.
--
So they are even more frightened than we are, he thought. Why, is this
all that's meant by heroism? And did I do it for the sake of my country?
And was he to blame with his dimple and his blue eyes? How frightened he
was! He thought I was going to kill him. Why should I kill him? My hand
trembled. And they have given me the St. George's Cross. I can't make it
out, I can't make it out! +-Leo Tolstoy, "War and Peace"
Laura Bush murdered her boy friend
Bill Bonde ('by a commodius vicus of recirculation') wrote:
> laura bush - VEHICULAR HOMICIDE wrote:
> >
> > I'm sure the added weight hurts mileage in city driving where you do a
> > lot of accelerating. But in constant speed driving like on a freeway,
> > i would think the reduction is very slight.
> >
> So you also think that adding a trailer to a car doesn't affect highway
> mileage much? At what point does it start to matter? And if putting a
> few fat people in your car doesn't matter, then why does it matter if
> you drive alone in your SUV, using the extra weight of passengers for
> the extra features of the SUV.
You missed the point entirely. A trailer greatly increases wind
resistance while passengers in your car do not. I guess i should have
explained that but i just assumed even you could see that.
Larry Bud
The car doesn't know the difference between drag and weight. Hell, you
bitch and moan all the time about the BIG GAS GUZZLING SUVs. Why the
hell do you think they suck down so much gas? Hint, the weight.
You have a 3000lb car, and you add 3 200 pound passengers. You've just
increased the weight by 20%.
223rem
> The car doesn't know the difference between drag and weight.
There is a difference. Increased weight increases "mechanical" friction
(tire-road, as well as transmission friction).
(please dont x-post)
Larry Bud
True, I should have said the ENGINE doesn't know the difference between
drag and weight. As far as it's concerned, it's a load.
Laura Bush murdered her boy friend
Larry Bud wrote:
> Laura Bush murdered her boy friend wrote:
> > Bill Bonde ('by a commodius vicus of recirculation') wrote:
> > > laura bush - VEHICULAR HOMICIDE wrote:
> > > >
> > > > I'm sure the added weight hurts mileage in city driving where you do a
> > > > lot of accelerating. But in constant speed driving like on a freeway,
> > > > i would think the reduction is very slight.
> > > >
> > > So you also think that adding a trailer to a car doesn't affect highway
> > > mileage much? At what point does it start to matter? And if putting a
> > > few fat people in your car doesn't matter, then why does it matter if
> > > you drive alone in your SUV, using the extra weight of passengers for
> > > the extra features of the SUV.
> >
> > You missed the point entirely. A trailer greatly increases wind
> > resistance while passengers in your car do not. I guess i should have
> > explained that but i just assumed even you could see that.
>
> The car doesn't know the difference between drag and weight.
Idiot. The wind resistance stays the same no matter what the car
weighs. And for freeway driving at a constant speed wind resistance is
the big determinant in mileage.
Bill Bonde ('by a commodius vicus of recirculation')
Laura Bush murdered her boy friend wrote:
>
So you think that it is just wind resistance that increases the use of
gasoline? How about putting a ton of rock chip in your pickup bed. Does
that change your mileage?
fsds...@yahoo.com
Bill Bonde ('by a commodius vicus of recirculation') wrote:
> Laura Bush murdered her boy friend wrote:
> >
> > Bill Bonde ('by a commodius vicus of recirculation') wrote:
> > > laura bush - VEHICULAR HOMICIDE wrote:
> > > >
> > > > I'm sure the added weight hurts mileage in city driving where you do a
> > > > lot of accelerating. But in constant speed driving like on a freeway,
> > > > i would think the reduction is very slight.
> > > >
> > > So you also think that adding a trailer to a car doesn't affect highway
> > > mileage much? At what point does it start to matter? And if putting a
> > > few fat people in your car doesn't matter, then why does it matter if
> > > you drive alone in your SUV, using the extra weight of passengers for
> > > the extra features of the SUV.
> >
> > You missed the point entirely. A trailer greatly increases wind
> > resistance while passengers in your car do not. I guess i should have
> > explained that but i just assumed even you could see that.
> >
> So you think that it is just wind resistance that increases the use of
> gasoline? How about putting a ton of rock chip in your pickup bed. Does
> that change your mileage?
The highway mileage my 2000 VW GTI got with just me in it was 33mpg.
Add my wife and ~600 more pounds of stuff and it only dropped to 31.5
mpg. Weight only does so much when going steady speed. The reason
SUV's get such bad gas mileage on the freeway is the much greater
frontal area multiplied by a higher COD compared to a car.
Guy
<fsds...@yahoo.com> wrote in message
news:1127248142.9...@g43g2000cwa.googlegroups.com...
Adding weight to a car will increase the tire footprint, increasing the
rolling resistance. It's not as significant as wind resistance.
Harry K
Has more to do with accelerating and maintianing speed on a heavier
loaded vehicle. Just maintaining speed going up an incline has the
same effect on the engine as acclerating on a level surface. You lose
more going up hill than you get back going down.
Harry K
Mike Tantillo
Actually, wind resistance, in terms of force (pounds, kilograms, etc)
increases with vehicle speed. Meaning a car that experiences 20 pounds
of drag at 30 MPH may experience 50 pounds of drag at 60 MPH. (I made
the numbers up for this example).
Laura Bush murdered her boy friend
We're talking about the case where the speed is the same. All that
changes is the weight INSIDE the vehicle and the vehicle is NOT
accelerating.
Laura Bush murdered her boy friend
Bill Bonde ('by a commodius vicus of recirculation') wrote:
> Laura Bush murdered her boy friend wrote:
> >
> > Bill Bonde ('by a commodius vicus of recirculation') wrote:
> > > laura bush - VEHICULAR HOMICIDE wrote:
> > > >
> > > > I'm sure the added weight hurts mileage in city driving where you do a
> > > > lot of accelerating. But in constant speed driving like on a freeway,
> > > > i would think the reduction is very slight.
> > > >
> > > So you also think that adding a trailer to a car doesn't affect highway
> > > mileage much? At what point does it start to matter? And if putting a
> > > few fat people in your car doesn't matter, then why does it matter if
> > > you drive alone in your SUV, using the extra weight of passengers for
> > > the extra features of the SUV.
> >
> > You missed the point entirely. A trailer greatly increases wind
> > resistance while passengers in your car do not. I guess i should have
> > explained that but i just assumed even you could see that.
> >
> So you think that it is just wind resistance that increases the use of
> gasoline? How about putting a ton of rock chip in your pickup bed. Does
> that change your mileage?
It will change the mileage if you're accelerating a lot as in city
driving. But as originally asked, will it have much of an impact on
constant speed driving as on a freeway?
Larry Bud
No shit. Read it again. Drag affects fuel consumption as does weight.
The engine doesn't know the difference between the two.
laura bush - VEHICULAR HOMICIDE
wrote:
You are a COMPLETE EMMEFFING MORON with no physical intuition at all.
Bill Funk
<xeto...@yahoo.com> wrote:
>>> Idiot. The wind resistance stays the same no matter what the car
>>> weighs.
>>
>>No shit. Read it again. Drag affects fuel consumption as does weight.
>> The engine doesn't know the difference between the two.
>
>You are a COMPLETE EMMEFFING MORON with no physical intuition at all.
That's telling him!
You're stupid, and wrong, but you really told him!
Good on yer!
--
Bill Funk
Replace "g" with "a"
funktionality.blogspot.com
Dick Boyd
Pressure goes as the square of the velocity, power required as the cube
of velocity as a first approximation.
Doubling the speed would result in four times as much wind resistance
or drag. Or whatever name you want to give to pushing air out of the
way. Typical air resistance drag for a passenger automobile is in the
range of 50 to 85 pounds at 50 MPH, depending on area (18 to 23 sq.ft.)
and drag coefficient (0.27 to 0.55). Total drag is in the range of 90
to 200 pounds. (15 to 20 horsepower [11 to 15 kW]).
BTW, air resistance is the ultimate "speed limit". Air resistance
determines how much the engine can breathe. Air resistance is the
limiting force at speed.
Significant forces at steady speed are tire deformation and air
resistance. Unless the tires are underinflated to begin with or the car
is loaded beyond nameplate data, or the car has the wrong tires
installed.
Cold tires may have more effect on drag than the weight carried. Tire
resistance is about 25% greater during the first 10 minutes of
movement. It may take as long as 20 minutes to reach equilibrium
temperture.
The technical term "aero horsepower" is used to denote power required
to overcome air drag at 50 MPH on a level highway.
A reduction of 1 aero horsepower is the fuel-efficiency equivalent of
taking 300 pounds out of the car. But fuel reduction is more a factor
of acceleration. 300 pounds increase in weight increases fuel
consumption (CAFE cycle) by about 1% (0.3 MPG at highway speed, 0.8 MPG
city driving).
Aero Horsepower of a mid size car is about 7 to 8.
For the population in general, "underinflated" tires seems to be the
norm. Underinflated tires is related to ride comfort. People like a
softer ride and the roads aren't all that smooth. Except in North
Carolina. For the motoring public in general carrying unneeded weight
in the trunk seems to be the norm.
TedKennedyMurderedHisP...@spamgourmet.com
Can you even *GET* an SUV doors closed when you're trying to load your
fat, lazy, incompetent ass into one?
TedKennedyMurderedHisP...@spamgourmet.com
Like you have a freakin' clue? Way to NOT address the issue, retard.
~^Johnny^~
Rolling friction might increase ever-so-slightly because the tires
flatten out a little, and there is more lateral stress on the wheel
bearings, as well as torsional friction in the power train, however,
a couple of bodies more drastically increases the power-to-weight
ratio, which, relatively, affects efficiency during heavy
acceleration and braking (city driving).
In other words: 20% cargo weight added to gross weight affects
economy during city driving economy far much worse than it does
during highway driving.
--
-john
wide-open at throttle dot info
~^Johnny^~
<xeto...@yahoo.com> wrote:
>for freeway driving at a constant speed wind resistance is
>the big determinant in mileage.
What about grade? ;->
~^Johnny^~
wrote:
>Actually, wind resistance, in terms of force (pounds, kilograms, etc)
>increases with vehicle speed.
It is exponential, to the third power.
Doubling velocity increases wind resistance by a factor of eight!
~^Johnny^~
>Pressure goes as the square of the velocity, power required as the cube
>of velocity as a first approximation.
Yes.
>Doubling the speed would result in four times as much wind resistance
>or drag.
Well, no. Power equals velocity cubed.
It may be four times the "resistance", due to pressure alone, but
it's at twice the velocity, so it still takes eight times power from
the moving object to overcome the wind drag.
To move air, power required to move a propeller varies as the cube of
the velocity of the propeller moving it. Volume, OTOH, is directly
proportional to propeller velocity, while absolute pressure is
proportional to its velocity squared.
Yes, these are ideal approximations, according to basic fan laws.
http://www.vent-axia.com/sharing/fanlaws.asp
--
-john
wide-open at throttle dot info
~~~~~~~~
Always listen to experts. They will explain what
can't be done and why. Then do it. - Robert Heinlein
~~~~~~~~
~^Johnny^~
wrote:
> Just maintaining speed going up an incline has the
>same effect on the engine as acclerating on a level surface.
BINGO!
100% true.
Alan Baker
~^Johnny^~ <nos...@gyrogearloose.com> wrote:
> On 21 Sep 2005 21:31:05 -0700, "Dick Boyd" <dick...@aol.com> wrote:
>
> >Pressure goes as the square of the velocity, power required as the cube
> >of velocity as a first approximation.
>
> Yes.
>
> >Doubling the speed would result in four times as much wind resistance
> >or drag.
>
> Well, no. Power equals velocity cubed.
Well, yes.
Drag would be doubled, but as power is equal to force times speed (and
speed is double), power would be cubed.
>
> It may be four times the "resistance", due to pressure alone, but
> it's at twice the velocity, so it still takes eight times power from
> the moving object to overcome the wind drag.
Which is what he said.
>
> To move air, power required to move a propeller varies as the cube of
> the velocity of the propeller moving it. Volume, OTOH, is directly
> proportional to propeller velocity, while absolute pressure is
> proportional to its velocity squared.
>
> Yes, these are ideal approximations, according to basic fan laws.
>
> http://www.vent-axia.com/sharing/fanlaws.asp
>
>
> --
> -john
> wide-open at throttle dot info
>
> ~~~~~~~~
> Always listen to experts. They will explain what
> can't be done and why. Then do it. - Robert Heinlein
> ~~~~~~~~
--
Alan Baker
Vancouver, British Columbia
"If you raise the ceiling 4 feet, move the fireplace from that wall
to that wall, you'll still only get the full stereophonic effect
if you sit in the bottom of that cupboard."
~^Johnny^~
<nos...@gyrogearloose.com> wrote:
>On 20 Sep 2005 18:53:57 -0700, "Mike Tantillo" <mjtan...@yahoo.com>
>wrote:
>
>>Actually, wind resistance, in terms of force (pounds, kilograms, etc)
>>increases with vehicle speed.
>
>It is exponential, to the third power.
>Doubling velocity increases wind resistance by a factor of eight!
Oops! By a factor of four, actually. Sorry about that.
Power, not resistance. My bad. It's late.
When I think of win resistance, I think of total power loss, not
just the resistance.
But still, "Eye-Squared-Are", as in electronics. <g>
4x resistance at 2x velocity requires 8x power.
~^Johnny^~
wrote:
>In article <cnlhj1p52b76t84te...@4ax.com>,
> ~^Johnny^~ <nos...@gyrogearloose.com> wrote:
>
>> On 21 Sep 2005 21:31:05 -0700, "Dick Boyd" <dick...@aol.com> wrote:
>>
>> >Pressure goes as the square of the velocity, power required as the cube
>> >of velocity as a first approximation.
>>
>> Yes.
>>
>> >Doubling the speed would result in four times as much wind resistance
>> >or drag.
>>
>> Well, no. Power equals velocity cubed.
>
>Well, yes.
>
>Drag would be doubled, but as power is equal to force times speed (and
>speed is double), power would be cubed.
>
>>
>> It may be four times the "resistance", due to pressure alone, but
>> it's at twice the velocity, so it still takes eight times power from
>> the moving object to overcome the wind drag.
>
>Which is what he said.
Yes. Gotcha.
I was thinking in terms of power.
Resistance is futile.
As a 30 year veteran Ham Radio Operator, I should know teh difference
between power and resistance. :-O
In a senior moment, I got my terms mixed up.
That's why I retired. :-)
~^Johnny^~
<xeto...@yahoo.com> wrote:
Are we on the level?
Alan Baker
~^Johnny^~ <nos...@gyrogearloose.com> wrote:
I understand it happens to all of us eventually, and I'm getting closer
to retirement than I am to high school myself. I hope I take my
momentary lapses -- senior moments or no -- with as much grace.
Cheers
Pooh Bear
Larry Bud wrote:
> The car doesn't know the difference between drag and weight.
Yes it does.
Weight simply adds to the kinetic energy involved in acceleartion and braking.
Drag is a *constant* drain on the engine. Added drag will cause poor mpg. Added
weight will likely have just a small effect.
Graham
Pooh Bear
> Laura Bush murdered her boy friend wrote:
> >
> > Bill Bonde ('by a commodius vicus of recirculation') wrote:
> > > laura bush - VEHICULAR HOMICIDE wrote:
> > > >
> > > > I'm sure the added weight hurts mileage in city driving where you do a
> > > > lot of accelerating. But in constant speed driving like on a freeway,
> > > > i would think the reduction is very slight.
> > > >
> > > So you also think that adding a trailer to a car doesn't affect highway
> > > mileage much? At what point does it start to matter? And if putting a
> > > few fat people in your car doesn't matter, then why does it matter if
> > > you drive alone in your SUV, using the extra weight of passengers for
> > > the extra features of the SUV.
> >
> > You missed the point entirely. A trailer greatly increases wind
> > resistance while passengers in your car do not. I guess i should have
> > explained that but i just assumed even you could see that.
> >
> So you think that it is just wind resistance that increases the use of
> gasoline? How about putting a ton of rock chip in your pickup bed. Does
> that change your mileage?
If driving at a constant speed it would make quite a minor change to the mpg.
It'll show up badly if much acceleration and braking is the case though ( as in
urban driving ).
Graham
cLIeNUX user
It might also show up more in a tiny (i.e. light) car like a Geo Metro.
>Graham
>
At 60 mph in a normal car overcoming wind resistance is roughly 90% of the
load of maintaining speed. No. Passenger weight is not noticeable, while
tiny streamlining mods are. Of course, PASSENGER mpg jumps with each
passenger. 20 mpg with 4 passengers is 80 passenger mpg. A bus getting 6
mpg might be getting 480 passenger mpg with 40 passengers.
A slick kit-car body on a VW Beetle could be worth 5 mpg on top of a
Beetle's already good mileage due mostly to streamlining.
--
Rick (Richard Allen) Hohensee Party of one
candidate, President of the United States of America
humb...@smart.net Maryland, USA
Ground troops out of Iraq Put the CIA under INS
Semi-legalize drugs Prosecute Bush Tighten the borders
Isolate Israel Tax churches halve military aquisitions
platform ftp://smart.net/pub/humbubba/platform2
cLIeNUX user
>
>
>Larry Bud wrote:
>
>> The car doesn't know the difference between drag and weight.
>
>Yes it does.
>
>Weight simply adds to the kinetic energy involved in acceleartion and braking.
>
Almost. Weight also adds to the rolling resistance. Overcoming tire
deflection is like mounting a small incline, and a heavier vehicle
deflects the tires more, increasing the 'incline'. This is a huge factor
with "pans", the rubber-tire road excavation gizmos that hold like 15 c.y.
(30 tons) of dirt.
>Drag is a *constant* drain on the engine. Added drag will cause poor mpg. Added
>weight will likely have just a small effect.
>
In the car world that's basically true. Pans and so on are another world.
>Graham
NunYa Bidness
us:
>Adding weight to a car will increase the tire footprint, increasing the
>rolling resistance. It's not as significant as wind resistance.
>
It also increases the energy required to traverse an incline.
Whether the tires get a bigger footprint or not.
Pooh Bear
cLIeNUX user wrote:
> humb...@smart.net
> >
> >
> >Larry Bud wrote:
> >
> >> The car doesn't know the difference between drag and weight.
> >
> >Yes it does.
> >
> >Weight simply adds to the kinetic energy involved in acceleartion and braking.
> >
>
> Almost. Weight also adds to the rolling resistance. Overcoming tire
> deflection is like mounting a small incline, and a heavier vehicle
> deflects the tires more, increasing the 'incline'. This is a huge factor
> with "pans", the rubber-tire road excavation gizmos that hold like 15 c.y.
> (30 tons) of dirt.
You're perfectly right but in normal cars the added footprint and rolling resistance
is quite small.
> >Drag is a *constant* drain on the engine. Added drag will cause poor mpg. Added
> >weight will likely have just a small effect.
> >
>
> In the car world that's basically true. Pans and so on are another world.
Sure.
Graham
cLIeNUX user
Yeah. One interesting remark about the double-nickel when it came out was
a trucker who said we need that speed to hit these hills. At 80,000 pounds
momentum is, uh, huge.
Pooh Bear
cLIeNUX user wrote:
Best of all are vehicles with bodies that are already streamlined. Another nail in
the SUV's coffin !
Graham