Emissions controls: Valid logic?

You are correct from my observations. I drive the last generation of carb Jeep engines and we can disable the emissions controller and manually tune the engines to get a sweet 25% seat of the pants power boost with about the same in mileage 'and' still pass the needed emission 'tailpipe' standards to boot!

A bunch of us have gone from a functional red line of 3500 rpm and 18 or less mpg to a red line of 4400 and closer to 23 mpg highway in our 80's Jeep CJ and YJ's.

I have also driven 70's vehicles with no emissions that got great mileage. Had a Mini that always got over 50 mpg and V8's that got 20 or more highway.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Jan/06 (More Off Road album links at bottom of the view page)

As you state it, yes.

Thing is; modern emissions controls reduce emissions by much more than 10% compared to pre emission control.

Typical 1960s era emissions (no emission controls) were; HC 10.6 grams per mile CO 84 grams per mile NOx 4.1 grams per mile

1978 is the oldest model year I have standards for. The federal cut points were; HC 1.5 grams per mile CO 15.0 grams per mile NOx 2.0 grams per mile 2007 Federal cut points are HC .41 grams per mile CO 3.4 grams per mile NOx .4 grams per mile

The big three as listed above plus evaporative losses from the fuel storage plus others...

Impossible to compare since most engines in current compliance were not available pre emissions control. A late model 4.6 liter full sized Ford gets way better fuel mileage that a comparably sized model/engine would have back in the 60s.

A late model Mustang will eat a 60s era Mustang.

Because the cars sold today have more creature comforts/safety add ons than those sold 37 years ago and the fact that you cite two somewhat obscure examples. A typical 1970 model year car would have gotten around 15 MPG. And, as I've shown above, grossly different WRT tail pipe emissions.

My 1998 Full size Dodge w/3.3 liter engine cracks 30 MPG, 30 MPG is not unusual for a full sized Buick w/3.8 liter engine. A newish Corvette probably gets close to 30 MPG driven sanely.

Which also brought us; better driveability reduced maintenance improved reliability

Those 'tailpipe' standards that you're passing have nothing to do with the emissions standards that the vehicle was engineered to meet when it was sold new. (but you knew that)

New would be lower for sure but on these older engines a manual tune will do the same if not better in some cases than the stock Ford emissions computer does. We have had a chance to compare a bunch.

These old Jeep 258's actually tune up really clean which is nice. You just have to 'keep' them tuned up which the computer can do better than most folks 'want' to do....

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Jan/06 (More Off Road album links at bottom of the view page)

aarcuda69062 wrote in news:nonelson- snipped-for-privacy@newsclstr02.news.prodigy.com:

For example...

My 1991 Honda was meant to emit

0.10% CO at idle when new. This according to the factory shop manual.

My province's emissions test (patterned after Georgia's) allows

1.0% CO at idle.

My last test showed

0.61% CO at idle, this at 287,000 miles with the original cat.

aarcuda69062 wrote in news: snipped-for-privacy@newsclstr02.news.prodigy.com:

Reductions of the various tested gases from 1970 to now range from 80% to

99%, from what I've read.

Gas mileage has not declined by that much, I'm sure.

You can thank computerized feedback systems for all the improvements.

Could you have imagined a 400hp V10 with impeccable idle and driveability, plus 15mpg and low emissions, in 1978?

"Proctologically Violated©®" wrote in news:dp03i.21$ snipped-for-privacy@newsfe12.lga:

Honda through the '90s routinely produced Civics with 1.5L gasoline engines that returned close to 40mpg.

My gasoline 1.8L Integra gets a high of 30mpg in the summer, and a low of

27mpg in the winter. And that's with 287K miles and a steady diet of 80mph highway driving.

The wife's gasoline 1.5L Tercel gets 33mpg summer, 30mpg winter.

So where's the miracle?

As someone else has posted it is more like 90% to 99%, maybe more.

No. The pollutants emissions are measured in g/km or g/mile, not in grams per fuel consumed.

1970 is surely a bad example, because it was before the first oil crisis, when engines were not particulary efficient, aerodynamic drag was high (cx > 0.4), etc. Now if you compare cars from the 80s, after _two_ oil crisis, good aerodynamics (cx was reduced to around 0.3), etc. things are different.

And the reason for that is because the cars have almost doubled in weight (I am talking about European/Japanese cars). For instance a Golf GTI, 1st generation weighted about 840 kg. The current model is around 1500 kg and so needs (and has) a lot more power to be considered a sports car.

But these days a car needs (marketing wise, not legally) a 5-star NCAP safety rating and that weights (recent models, for instance from the Renault Clio and Peugeot 207 have increased in weight some 150-200 kg and almost all of that was in safety structure).

Another thing that doesn't help is the tendency for taller cars. Aerodynamic drag is proportional to S.cx in which S is front surface area and that obviously increases for tall cars. (As a car designer complained in an interview I read "people are paying for transporting air" (empty space) "around".)

And yet another thing is wider tyres. Which are a good thing for active safety, but cost fuel to carry around.

It would be very easy to make a car capable of 3l/100km or better: start with a 1990 Citroen AX with its 700kg or so, skinny tyres, good aerodynamic, put a 1.0l or smaller turbodiesel in it and it would consume even less than the original 1.4l non-turbo diesel (and I had drivers of those telling me that they got around 3.5l/100km in real life (obviously driving a bit like in a econo-run)).

Only problem is, nobody would buy it: it is too small (you can fit 4 or

5 adults in it but not very confortably), its NCAP rating would be about 2-stars or less and it would not have the equipment people expect these days. In fact VW did something like it some years ago. Was it a Lupo or a Polo ? Anyway, it was marketed as a 3.0l/100km car, but in practice didn't get that and nobody bought it anyway (it was a bit expensive for what it was).

In gasoline engines the big penalty for pollutants controls was when engines went from lead fule without catalysts to non-lead fuel and catalysts. That was more than 15 years ago (in Europe) and the drop in efficiency was problably overcome by now with more sophisticated engine management, 4 valves per cylinder, etc.

But one thing in which pollutants controls are increasing fuel consumption a bit is in turbo-diesels. For highest efficiency you want all the fuel to be burned in one go, but for reducing pollution recent engines do as much a 5 injections in one cycle. And the particle filters restrict the exhaust and some fuel is used to burn the soot in that once every 1200 km or so.

But, in the 2007 CR car issue, only two Dodge's get over 20 mpg: the Caliber ( 24, 4 cyl), and the Avenger (21, V6) Not a single Buick, V6 or otherwise, cracked 20 mpg's. Whazzup wit dat??

The 'Vette doesn't do too bad, at 19 mpg. The Dodge Durango gets 12. :) My '79 Cougar got 25-30 mpg, iirc. 305 V8. :)

First off, the source. Consumer report typically doesn't like to see domestic vehicles fare well in their tests.

I have to tell you, I've been a mechanic since before your 79 Cougar was built, I highly doubt that it got 25-30 MPG. The technology used back then was archaic, Rube Goldberg crap. The engines were very low compression, the spark timing was antiquated, the fuel delivery was akin to a flush toilet.

I've heard that, but bleeve me, they are not picking on domestics in this regard. Hardly *any* midsized vehicle cracks the 20 mpg mark, and the Yaris, distinctly UN-recommended by CR, gets "only" 33 mpg, the highest I was able to find. The Fit was second, w/ 32. And highly rated.

And, Ford made surprising headway into the Best Picks list. Not their trucks, but the Focus/Fusion, iirc. wow.... Also the Vibe, which is a Matrix clone.

Yeah, it's been so long I couldn't swear to those mpgs, but I'm sure it was as good as my replacement 1990 Mazda 929S 3.0L V6. And, the Cougar caught fire THREE times, and ran fine after each fire was put out. The last fire made the brakes a little mushy/spongy, but I just hadda pump'em a little more furiously than before.