Does anyone know, or has anyone read or possibly calculated how much additional fuel is consumed by modern engines solely to satisfy pollution control or smog regulations?

Seems that just when technology became affordable to boost power and economy, the relentless barrage of additional and more restrictive environmental regulations drained away the gains of the newest technological innovations.

Thoughts, anyone?

 

Actually, I think both MPG goes up and smog goes down at the same time. At least that was the case when vehicles went from carb'd to EFI. I don't know if it's still true today, but I do know that at one point in time Saab was developing an engine recently that ran with 70% exhaust gas recirculation (EGR), and EGR is technically smog equipment. 70% EGR means incredible mileage.

In general, if you use less fuel, not only is your mileage increasing by definition, but you are emitting less polutants into the atmosphere. I would imagine, though, that there are exceptions, so I welcome people to dispute my claim.

 

This is 1960s thinking that the smog stuff "chokes" the power, augmented by the general misunderstanding of the change in SAE horsepower ratings that took place in 1972 or so which dramatically reduced already dropping hp numbers.

Yea, a lot of the early stuff reduced power and increase fuel use. The two major culprits were lowered compression and changed cam/ignition timing.

Fast forward. Some engines are running 11:1 CR these days thanks to that nastiest of nasty smog devices, the EGR set up.

If you look at the mpg, weight and hp of the overall fleet over the last 20 years or so, you will find:

--CAFE stays about the same

--Weight goes up quite a bit (New Civics are the size of old Accords, ditto Camry, and the F150 ---say no more...)

--HP goes up

All this while emissions have gone DOWN.

Take 500lbs on average out of the vehicles and 25 to 50 horse and the CAFE number takes a nice jump up.

BTW, why do you ask? Do you think emissions standards should be dropped for some increase in mpg? What is the motivation for this line of thought and questioning? Emissions laws are here to stay.

 

I think air injection pumps are one of the reasons why folks think that engines with smog reducing equipment means additional fuel is being burned to run it. Since modern engines don't have those air injections pumps anymore, I would say smog reducing equipment in general doesn't necessarily mean more fuel is consumed to "run" it. Electronics have taken car of that.

 

I believe the emissions stuff truely works now and doesn't hurt the gas engines.
But they didn't start getting it right until around the 90s.
The late 70s and early 80s had bad designes that did 'choke' the engines.


The stuff they are doing to diesels on the other hand is just wrong.
The diesel engine lives are shortening, mpg is droping, etc....

 

Ford's first engine with emissions in mind was the 4.6. It cut out a lot of the " band aids" that were on the previous engines. The engine has good power and gets pretty decent fuel mileage. On the other hand this 10% ethanol has dropped my 1989 Ford Squire wagon's mileage 1-2 mpg.

 

"Smog equipment is bad" is old thinking. Modern engines and computer controls allow us to have very nice vehicles with good performance and still get good mileage and low smog.

In the 60s and 70s, cars got "good" mileage due to much lower weight and few accessories like AC, crash protection, multiway seats, etc. Now cars come with lots of accessories that were unheard of or just luxuries in the 60s. But they still get better mileage than comparable older design cars. Compare a 1970 Toyota Corolla with a 2008. The mileage on the 2008 is just a dream for the 70s car and a typical modern Corolla has "luxuries" unthinkable in an econo box like the 70 Corolla, which if I recall was rated as UNACCEPTABLE and unsafe on American Highways due to lack of power, lack of protection and just plain cheap as Toyota could make it.

Look at Modern 250s with 460 engines such as my 94(the 2008's do even better). Compared to 70s/80s F250s with 460 engine, I believe that you will find my 94 has about 4+ mpg better and more towing power and could be considered as a "Cowboy Cadillac" in comparison to the brute work trucks from those eras.

When is the last time you had to do a real tuneup? Plugs, points condenser, carb rebuild, shall I go on? Modern engines tune themselves which means you have better than the performance and mileage of a "fresh" engine without the 12,000 mile hassle

Modern engines are designed to work best with the smog controls. Removing smog controls without understanding how everything works together can get you worse performance or mileage than just letting the computer do it's job. Sure you can sometimes get some performance improvements if you are lucky and don't remove key components, but in general, most people mechanically inclined will pass by a used vehicle that has been butchered by yanking controls. Usually desmogged engines have lost their driveabilty and sometimes reliability in exhange for hoped improvements.

Cars are much much better than they were in the 60's and 70s. About my only gripe with modern cars is that sometimes if a key computer component or sensor dies, you may not be able to find a replacement and may not be able to jury rig around it. Old cars could almost be forced to run, no matter what had been done to them

Just my opinions,

Jim Henderson

 

It's tough to remove things like pistons with high ring lands, cams, electronic ignition systems, variable cam timing...what else that's been worked on, worked over and worked in to the hard parts of the engine to reduce emissions.

See if you can improve the performace of arguably one of the best engines on the market today.

4.6l, 380 horse, 14.3 quarter despite 4500lb car, 11.8 : 1 CR, EPA 19city 27 highway, with a ultra low emissions rating.

Ahh, if you cut the cats off it and put some glasspaks on it, I bet it would into the 13s....

 

All I know is a customer's F-150 4.6L got almost 21 mpg on the highway, same as my much smaller Bronco II. I do not think the emissions is the problem, I think it is the additional weight of the newer vehicles.

 

http://www3.telus.net/cbradley/Engin...fications.html
Power to weight ratio is what you have to look at when comparing newer to
older vehicles. Have you seen that guy who made a Subaru wrx into a quad
basically he is sitting on the engine, trans and gastank. He steers with handle
bars and has a motorcycle seat I would guarantee it is faster and got way way
better fuel mileage and had less emissions especially if you drove it conservatively
side by side since the full body car has the aero drag and the weight penalty so
for a given speed it takes more go pedal and hence more fuel. Check out youtube
search for wrx quad.

 

I haven't been able to check in for a few days and I see we've been busy trying to answer my question.

But I am at fualt for not properly phrasing my question so that it would be easy to understand what I meant,

I will give it some more thought and try to figure out a way to explain what I meant.

But I can't now...must get sleep before work calls.

 

And I'm not takin' the bait.

 

That statement sounds like you'd could be tempted to tamper with a pollution control device!

 

I remember recently seeing a statistic stating that modern car engines size for size produce twice the power, get twice the MPG and produce 1/3rd the emissions of engines 30 yrs ago

 

That's wrong.

Twice the power and mpg... no, but more... yes!

IF a engine had 200 hp and 300 ft/lbs in the 70s and get 12mpg, no same size engine will produce 400 hp and 600 ft/lb...... maybe 300 hp and 350 ft/lbs, and still get 15 mpg.