What if "new CAFE requirements" ......

Status
Not open for further replies.
Joined
Dec 31, 2016
Messages
10,136
Location
Waco, TX
OK, PLEASE no politics to keep this from getting locked
( https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4710915/ )

Engineers, please step in.....

I have argued (well... ranted, really) for years
that if we just stop focusing on emissions to such a strict degree...
and focus on FUEL MILEAGE solely, instead -

That we COULD get cars that meet the new CAFE requirements.

High swirl combustion chambers, variable valvetrain events, etc... these make engine more "efficient".
"Efficient" is good, because mileage and power both go up.

Bu then throw in EGR, catalytic converters (not so much now as in the past), and other devices focused on emissions only. The diesel trucks guys have it horrible - doing a regen on a DPF uses tons of extra fuel (and makes more co2) - just so there's less particulates?!?!? To heck with particulates, look at all the extra co2 you're making!


Rant off (for now) -

Q: how efficient can engines really be if we could just forget about emissions and focus on fuel economy instead?
 
I know that running lean increases NOx emissions, and that some engines like to waste fuel just for the purpose of heating catalytic converters.
 
I don't think emissions is as a big a deal as basic physics. You need a smaller car with a smaller engine to hit those gas mileage number. It's very apparent that's going on as the V6 in the Accord is now gone and it's been replaced by a 4 cylinder. It's probably easy to hit those CAFE numbers if you have a little 3 cylinder one liter engine. Except no one would want to buy one or drive one.
 
Technology and engineering will get us there. When I was a kid, my mother had a '90 Cherokee that got like 12 MPG. My Grand Cherokee gets 24. I pulled into a parking spot a few weeks ago and parked next to an old 1990 Cherokee and the GC dwarfed it.
 
Originally Posted By: Wolf359
I don't think emissions is as a big a deal as basic physics. You need a smaller car with a smaller engine to hit those gas mileage number. It's very apparent that's going on as the V6 in the Accord is now gone and it's been replaced by a 4 cylinder. It's probably easy to hit those CAFE numbers if you have a little 3 cylinder one liter engine. Except no one would want to buy one or drive one.


I must be no one
 
Originally Posted By: Wolf359
I don't think emissions is as a big a deal as basic physics. You need a smaller car with a smaller engine to hit those gas mileage number. It's very apparent that's going on as the V6 in the Accord is now gone and it's been replaced by a 4 cylinder. It's probably easy to hit those CAFE numbers if you have a little 3 cylinder one liter engine. Except no one would want to buy one or drive one.


No...... 15 years ago I rode in a Corvette that was getting 27 MPG.

Explain that?
 
Back in the 1970s, lean burn, EGR, restrictions on vacuum advance in what gear, and at what throttle opening destroyed power, drivability, AND economy.

Catalytic Converters enabled them to make engines that ran, and were economical, AND had lower tailpipe emissions.

I think that we ARE (OK, we WERE) getting the best of both worlds when catalysts and Electronic Controls were married together.

But now there's some silliness...first popped up at BITOG with DI Audis that were purposely tuned differntly to their Euro specs, for emissions regulations, and had high fuel dilution and wear.

That's when we lost the plot.

If we continue to make emissions regs tighter and tighter, then it will, and is starting to hurt possible economy gains.

Bureaucrats continually "evolving" the targets to justify their existance is a problem...Would love to mention more about "Pollution reduction programmes" for heavy industry that are operating within licence limits, but wont.

Pick an emissions envelope, and leave it be while you chase economy.

If a new technology appears the significantly changes emissions, then move the targets, and ease back on the chase for economy until the new benchmark is established.

Moving both sets of goalposts at the same time causes problems.
 
Originally Posted By: dishdude
Technology and engineering will get us there. When I was a kid, my mother had a '90 Cherokee that got like 12 MPG. My Grand Cherokee gets 24. I pulled into a parking spot a few weeks ago and parked next to an old 1990 Cherokee and the GC dwarfed it.


I had a Holden Torana with 202 c.i. six...got 24MPG with 1970s emission strangulation. I worked the motor, changed the "tune" substantially, and got 32MPG (both are OZ MPG).

1978 Kingswood Wagon with 253 and auto. 15MPG. After messing with it seriously (and I mean seriously, with hot air intake, EGR, at idle, lower hose thermostat, PCV funes through a pipe wrapped around the headers), I got it up to 30MPG (Oz)...had free O2 in the exhaust.

Both would fail emissions tests in PPM, but produced less of them per mile, or gallon of fuel burned..
 
Originally Posted By: bubbatime
Diesel cars? Like the VW? They got good mileage, but bad emissions.


Define bad. We may be splitting fractions of a ppm of some combustion byproduct.

It's idiocy that a 12 MPG Ford SUV can be labeled a "partial zero" emissions vehicle, yet a 50mpg vw diesel is a "gross polluter". Which truly has the environmental impact?

I don't want to breathe soot or nod or stinky exhaust of any kind. But I suspect beyond a point, some of the byproducts will go away or be reduced as a focus on power output and efficiency are emphasized, over splitting ppm of something.
 
Originally Posted By: Shannow

Both would fail emissions tests in PPM, but produced less of them per mile, or gallon of fuel burned..


YES! See, that is where the focus should be

Originally Posted By: JHZR2
..... 12 MPG SUV can be labeled a "partial zero" emissions vehicle, yet a 50mpg diesel is a "gross polluter". Which truly has the environmental impact?


Yes. Why doesn't the EPA think about this?

A diesel Chevette or Rabbit from the early 80's makes smoke, but has way less co2.

Likewise, a weedeater gets thrown in the garbage after 20 hours (a huge environmental loss)
because the carb is too lean (to meet emissions).
It burns an entire 5 gallons of gas in it's 20 hour lifespan before failure.
"Low use, low fuel consuming items" should be exempt because they BURN LESS FUEL!!

I know my motorcycle wouldn't pass emissions... but it get 56 MPG.
It's gross co2 output in a YEAR is less than the average 9to5 weekday commuter is in a month.
 
Funny little anecdote...

Decades ago already, I bought a Ford Ranger with a 2.3 liter, Mazda M5R1 5sp OD trans, and 3.73 gears.
On a good day, I could get 25-26 MPG.

Power was abysmal. I couldn't even run the A/C up a hill in OD. Or into a strong wind, either!
I toyed with swapping in a 2.9 or 4.0 V6, but the M5R1 trans is made of glass & toothpicks.
I also really hate the V6 sound.

So...... with some careful scrounging, I swapped in a 5.0 V8, 5 sp OD, and dropped to 3.55 gears.
On a good day, I could get 23-24 MPG.

Over twice the engine displacement.... and nearly no loss in MPG (I actually hit 25 MPG once!)
 
I feel this way, we need CAFE to keep the automakers on their toes, but it's pushed too far when we now have small turbocharged engines in midsize cars and bigger trucks. And not everyone has OCD when it comes to maintenance like 99.998% of us here. But at the same thing, we're hitting the law of diminishing returns, and it might encourage Ford/GM/FCA to build more trucks and SUVs - yes, they are big, roomy and profitable for them but they won't get pressure to innovate. Look at what happened to them in the 1970s and again in the mid-2000s.

There was a theory that the Europeans focused on CO2 and NOx emissions since they are more prone to acid rain, while EPA/CARB focused on PM and HC emissions which are more immediate causes of smog, NOx does play a factor as well and the Asians targeted HC. Instead of CAFE as it is right now, why not have a CAFE for cars, MPVs and smaller trucks and a separate bin for heavy trucks(anything bigger than a Tacoma/Colorado/Ranger)? CARB might be hated, but in the towns that are home to major ports(Oakland/Long Beach/LA) and the Central Valley, every small bit of reducing emissions counts. Yes, the bros are grousing they can't roll coal anymore and truckers need to buy DEF and regens are a PITA but the technology is evolving. From what I've heard from a transit agency mechanic, they are having much less issues with SCR than with DPFs.

As it stands, the automakers would love to see CAFE rolled back. However, turbos, xDI, thin oil, micro-hybrids and electrification is here to stay. Toyota is kinda of bucking the trend of turbo GDI all the things - the 3rd and 4th gen Prius has a bigger engine(1.8L) in the paradox of higher efficiency === better gas mileage and lower emissions, their rationale is a bigger engine has to work less to stay in an optimal state between performance, emissions, consumption and reliability. They didn't turbo the Camry/Avalon/RAV4/Corolla - they somehow managed to strike a balance with their new Dynamic Force engine without the need for FI and the V6 is staying. They had to turbo the Lexus lineup because the Europeans are almost all TGDI now.
 
Last edited:
Originally Posted By: Linctex
Funny little anecdote...

Decades ago already, I bought a Ford Ranger with a 2.3 liter, Mazda M5R1 5sp OD trans, and 3.73 gears.
On a good day, I could get 25-26 MPG.

Power was abysmal. I couldn't even run the A/C up a hill in OD. Or into a strong wind, either!
I toyed with swapping in a 2.9 or 4.0 V6, but the M5R1 trans is made of glass & toothpicks.
I also really hate the V6 sound.

So...... with some careful scrounging, I swapped in a 5.0 V8, 5 sp OD, and dropped to 3.55 gears.
On a good day, I could get 23-24 MPG.

Over twice the engine displacement.... and nearly no loss in MPG (I actually hit 25 MPG once!)


I've experienced exactly that...

The Holden Torana platform had 1.9L Holden 4, 2.0L Opel, 2.85L Holden 6, 3.3L Holden 6, 4.3 V-8, and 5.0 V8.

I've had 1.9, 3.3, 4.2, and 5.0 back in the 80s and 90s.

ALL got 28+MPG (Oz) on the highway...road load was the same.

Around town, the V-8s used at least 1/3 more fuel (but made merging/cutting into traffic much "easier"...read fun)
 
Focusing strictly on car emissions is like looking at the world through a toilet paper tube anyway. We can, and, have, made cars that emit little to no emissions, but because the fundamental need to move weight around (F=MA) is still the same, the emissions output simply shifted to power plants or hazardous battery mfg/waste.
 
In 1970 I purchased a new E300 Ford Econoline van with a 302 V8, manual transmission and tuned up to factory spec's it passed California smog. I put larger main jets in the 2-barrel carb and carefully matched the porting on the carb to the manifold. I also advanced the static timing and changed the advance spring to allow the timing to advance quicker. The driveability improved a lot. It also blew better numbers in the smog test, too. A Ford mechanic wrote down exactly what I did including the P/N of the jets and springs. He used this method to satisfy customers that complained about stumbling acceleration in pickups and vans. He had to set the timing to stock and change the advance springs to make up for the retarded static setting.

I always wondered where Ford got the tune-up and carb settings.
 
The problem with statistics is, you can make them say literally anything you want if you filter it in a way that "proves" your point. That's why politicians love them.

The issue is that reality does not match up with cherry-picked statistics and/or selectively manipulated data; it's simply not the "end of the world as we know it" since 99%+ of climate is controlled by that big flaming ball in the sky. Increased CO2 levels result in increased plant life density, which... OMG... results in more O2 being returned to the atmosphere.

I really don't know how you could ever ignore the reality that using less fuel overall will, by definition, result in less combustion byproducts... instead of chasing emissions first. Last time I checked, used batteries are treated as hazardous waste; everything that comes out of a tailpipe is already part of the atmosphere
smile.gif
 
What wil cars cost in Calif and those states that require vehicles that meet the "old" EPA standards?

A great divide in auto specs will cost us all at purchase time, correct?
 
Originally Posted By: SubieRubyRoo


I really don't know how you could ever ignore the reality that using less fuel overall will, by definition, result in less combustion byproducts...


This statement is absolutely correct. However, how you burn the fuel defines what those combustion byproducts are, not all combustion events are created equal. You can burn a little fuel and have a lot of nasty byproducts or burn a lot of fuel and have a few nasty byproducts.

There is a happy medium there somewhere and differences in opinion on how to get there. If you look at Euro vs US emissions standards one allows more CO and less NOx while the other is reversed. Just different ways to reach similar compromises.
 
Status
Not open for further replies.
Back
Top