Does emissions equipment hurt gas mileage?
Jesse
modern emissions equipment helps or hurts gas mileage. He contends
that if engines were able to run without all of the emission controls
we would see an increase in gas mileage. I say that the emissions
controls help cars get better gas mileage since the fuel to air ratio
and ignition timing is supposed to be more accurate.
Anyone have anything to say about this?
HLS
"Jesse" <jbo...@gmail.com> wrote in message
news:538e83b7-4897-4121...@v23g2000pro.googlegroups.com...
Just my opinion....the initial pollution control devices made cars that
didnt run
well and didnt get good mileage at all. Now we can get good mileage and
good
power out of engines that are heavily modified to control emissions.
If you want to go back to the carburetor and distributor setups and take off
all
emission controls, I think you will still get poor power and poor mileage.
Vic Smith
wrote:
Seems to me the only real "equipment" is the EGR and cat.
Early EGR's weren't too good, but if you look at EGR in wikipedia
the suggestion is that modern EGR's get more out of the gas than
they cost.
So I think you're right.
--Vic
Hachiroku ハチロク
It's less 'emissions controls' and more 'engine management' these days.
The early days were ways to try and keep smog down, now it's more about
burning fuel more efficiently.
Kevin
news:rn9r15115r4rvbrcr...@4ax.com:
If you could have a modern eng optimised for no emision equip.then it
would get better milage. if you just took the emision equip. off a
preexisting eng.then it wouldn`t get as good. So your kinda both right
and wrong. KB
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Tegger
@v23g2000pro.googlegroups.com:
Engine control these days is all about the cat (God save the cat!). The
mixture is "accurate" for the cat, and also for reducing the Holy Trinity
of HC, CO and NO. It is not necessarily "accurate" for other
considerations. This can mean a mixture that is richer than it otherwise
might be, and thus lower mileage.
I believe you could get better mileage in modern cars at cruise if the
mixture were allowed to run leaner than it currently is during cruise.
Mileage is enhanced by extended driving at light-throttle cruise. Light-
throttle cruise, however, also elevates NO emissions. To correct that,
either the mixture is enriched and the timing retarded, or an EGR system
feeds inert gases into the combustion chamber, wasting some of the
cylinders' effective volume. Both of these will reduce gas mileage.
I also believe that the engineers have mastered the art of engine control
to the point where they have achieved /significant/ gains in fuel
efficiency during cold operation, acceleration and deceleration, and at
idle. These gains possibly more than offset any mileage lost due to cruise
enrichment, volumetric efficiency loss or other emissions-related changes.
I've so far ignored computerization, which is at the heart of the modern
engine. Other industries, bidden only by the profit motive and not by
government edict, have computerized very heavily since 1981, to the great
benefit of them and their customers. There's no way of telling now, but I
suspect engine controls would have eventually been computerized even in the
total absence of any emissions controls at all. And with computerization
would have necessarily come cleaner, more efficient engines. Maybe not
/quite/ as clean as we have now, but likely significantly less expensive
ones, and ones with possibly better gas mileage.
Could you get back the large cost of mandated emissions controls through
any resulting better gas mileage? I'm not sure. There must be a reason some
poorer parts of the world until very recently still had non-feedback FI and
carburetors.
But hey, why post here? Ask Tom and Ray (AKA "Click and Clack, the Tappet
Brothers"). Your question is right up their alley, and I've not yet seen
anyone else ask it. www.cartalk.com
--
Tegger
ben91932
> Seems to me the only real "equipment" is the EGR and cat.
Like some have mentioned, cars now are a whole 'package', and dont
have alot of emissions control equipment tacked on like they used to.
The days of heavily plumbed egr and air injection, spark controls and
heat risers are over.
> Early EGR's weren't too good,
That is an understatement!
EGR reduces NOX, and early systems were incredibly problematic,
sometimes causing massive hesitations, power loss and poor mileage.
If it was disconnected, many cars would detonate fiercely.
I made alot of money off of those crappy systems...
>but if you look at EGR in wikipedia
> the suggestion is that modern EGR's get more out of the gas than
> they cost.
Very true.
One of the last frontiers of effeciency improvements is reduction of
pumping losses, the work wasted by the engine pulling against a vacuum
on the intake stroke.
Since the early '80's, engineers have used egr as a way to increase
throttle openings at cruise to reduce pumping losses by diluting the
intake charge with exhaust gas as well as to control NOX.
Bottom line IMHO; your father was right in 1976, you are right now.
HTH,
Ben
Scott Dorsey
Modern cars don't have any "emissions equipment." They have tightly
designed engine systems that are designed as a unit.
Cars back in the seventies had "emissions equipment" that was tacked
on to solve issues like the fact that the engines weren't burning very
efficiently. Modern engines are designed to burn efficiently in the
first place, and they have closed-loop control systems to make them do
that. The control systems aren't "emissions equipment" at all.
There are some things on modern cars, like catalytic converters, which
might reduce fuel economy slightly. And it's possible that if you went
into the ECU code and decided to optimize it for best economy rather
than good emissions performance you might be able to get a little more
mileage out. But this isn't being done by "removing emissions equipment."
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Jesse
Thanks for the responses. Very informative. I'll have to remember all
of this for next time I see my father in law.
HLS
"Scott Dorsey" <klu...@panix.com> wrote in message
news:gvkkd3$9da$1...@panix2.panix.com...
The whole system is "emissions equipment" nowadays, I think. Everything is
too integrated to be able to separate a few parts and call it "de-smogging".
Go back to the era when carburetors, mechanical distributors, etc were in
vigor and I dont think you will get either decreased emissions nor good fuel
economy.
Paul Hovnanian P.E.
ratio, cam, air-fuel and ignition timing curves, then yes, you could get
better mileage. But this would mean disregarding emissions performance
(NOx in particular, since that places an upper limit on combustion
pressures).
Ripping the emission control h/w off of an existing car won't buy you
much. It might drive the ECU into some 'limp home' mode and actually
cost you performance and fuel.
--
Paul Hovnanian mailto:Pa...@Hovnanian.com
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Don Stauffer
The very large engines being put into cars are much more of a milage hit
than the emission controls.
Do we really need 0-60 times in the 7 second range rather than 9-10
seconds? The result of the monster engines is the operation during
normal driving at very low throttle and effective CR, really hurting gas
milage.
Hey, I am as much a gearhead as anyone, and love high performance cars.
I bought an old vintage race car to run in vintage events and get my
thrills on the track instead of the highway. I gave up my Dodge R/T and
got a Prius.
Ulysses
"Jesse" <jbo...@gmail.com> wrote in message
news:538e83b7-4897-4121...@v23g2000pro.googlegroups.com...
I don't know the answer but if you look at this chart:
http://www.therangerstation.com/Magazine/summer2008/fuel_mileage.htm
you can see that the mileage for a 1983 Ford Ranger was as high as 41 mpg
and for 2008 it's only 26. What does that tell us? It tells me that they
used to get better gas mileage. They also probably used to have much higher
emissions. My 1999 Ranger with a 3.0L auto has almost no emissions for NO
and HC. Probably pollutes just a little more than an electric car (well,
there is some CO2 also). To me it looks like I'm trading 15 mpg for cleaner
air.
I had a 1966 Mustang with a 289 ci V8 and a 3-speed auto trans. I got about
23 mpg and my foot was usually on the floor. I don't know how much a
comparable Mustang gets these days but I'd guess it's less.
Scott Dorsey
>The very large engines being put into cars are much more of a milage hit
>than the emission controls.
>
>Do we really need 0-60 times in the 7 second range rather than 9-10
>seconds? The result of the monster engines is the operation during
>normal driving at very low throttle and effective CR, really hurting gas
>milage.
We must have huge engines, because we all want huge and heavy car bodies
to compensate for our small penises. Therefore enormous engines are
required in order to accelerate to highway speed in any reasonable time.
>Hey, I am as much a gearhead as anyone, and love high performance cars.
> I bought an old vintage race car to run in vintage events and get my
>thrills on the track instead of the highway. I gave up my Dodge R/T and
>got a Prius.
Sure, but you probably don't have a penile inferiority complex like so
many other drivers do.
Scott Dorsey
>I don't know the answer but if you look at this chart:
>
>http://www.therangerstation.com/Magazine/summer2008/fuel_mileage.htm
>
>you can see that the mileage for a 1983 Ford Ranger was as high as 41 mpg
>and for 2008 it's only 26. What does that tell us? It tells me that they
>used to get better gas mileage. They also probably used to have much higher
>emissions. My 1999 Ranger with a 3.0L auto has almost no emissions for NO
>and HC. Probably pollutes just a little more than an electric car (well,
>there is some CO2 also). To me it looks like I'm trading 15 mpg for cleaner
>air.
I bet a nickel that the mass of the 1983 Ranger is a whole lot less than
that of the 2008. That's the real problem.
jim
Also the EPA changed the way they measure fuel economy. Some vehicles were rated
at as much as 1/3 less mileage under the new standards. That alone would account
for almost all the difference. I seriously doubt that an automatic was rated at
41 mpg back in '83.
-jim
HLS
"Don Stauffer" <stau...@usfamily.net> wrote in message
news:4a1e9a6d$0$89398
> The very large engines being put into cars are much more of a milage hit
> than the emission controls.
>
> Do we really need 0-60 times in the 7 second range rather than 9-10
> seconds? The result of the monster engines is the operation during normal
> driving at very low throttle and effective CR, really hurting gas milage.
>
> Hey, I am as much a gearhead as anyone, and love high performance cars. I
> bought an old vintage race car to run in vintage events and get my thrills
> on the track instead of the highway. I gave up my Dodge R/T and got a
> Prius.
My brand new 66 Mustang 289 225 hp got as good as the newer Sonoma
140 cid but it had twice the engine size.
Size is not everything, clearly.
Steve
Not all "emissions systems" are created equal.
EGR, for instance, hurts efficiency all by itself, but then auto
manufacturers discovered that they could use it as a way to control
detonation without retarding timing (it slows combustion not unlike
water injection). So a handicap got turned into an advantage.
Air injection pumps, which are rarely ever used any longer, were just a
parasitic draw on the engine and never helped efficiency.
PCV slightly hurts efficiency by enforcing a minimum airflow through the
engine, making it hard to do other things like idle very slowly and/or
shut down cylinders at idle without resulting in an over-lean mixture.
But PCV makes engines last a lot longer because it really cuts back on
gunk building up in the crankcase, acids in the oil, etc.
On the whole, I'd say that the auto makers have managed to adapt most
emission controls to the point that they are at worst a break-even.
Steve
> We must have huge engines, because we all want huge and heavy car bodies
> to compensate for our small penises. Therefore enormous engines are
> required in order to accelerate to highway speed in any reasonable time.
So you think that a guy with a Charger R/T is "compensating for
something" *more* than the guy with a Miata, SLK, Lexus IS, Acura NSX,
or 370Z?
I, for one, am much more likely to think the Miata/SLK/IS/NSX/370Z guy
is the one stuffing his shorts, spending hours in the gym (near the
mirror, of course), using corny lines at singles bars, and answering all
the male enhancement SPAM.
:-)
The guy with the Charger is happily married, getting plenty, and just
wants to carve a few corners AFTER he drops the kids off at school.
Steve
>
> I bet a nickel that the mass of the 1983 Ranger is a whole lot less than
> that of the 2008. That's the real problem.
> --scott
>
>
Yep. At a recent car club event, we had the opportunity to run a few
vehicles across a commercial truck scale. The results were interesting-
my '69 big-block R/T weighed 4050 pounds- about what I thought. A circa
2000 Ford Ranger v6 weighed 4200 lb- about 1200lb more than I would
think a "compact" pickup should.