New technology makes software-only AFM possible

Cowpie · February 2, 2015

Well, I can only base it on what others claim they get for mpg with their 2013 pickups with the 5.3L and 3.42 diff. I wouldn't pretend that mine does better or worse than another spec. But from what I have read from other folks that have same setup and still using the AFM, my mpg is right in line with theirs.

To be fair to GM, though I probably shouldn't be, their claims are valid on the AFM getting better mpg.... but... only on their computer simulations, dyno testing, and on their controlled proving ground test track. The semi truck engine OEM's are just as guilty of the same slight of hand magic tricks, but many of us in the the commercial trucking community have learned to see thru their claims also. But they deserve more credit than the auto and pickup OEM's, in that they have substantially raised average mpg numbers on their stuff while also increasing displacement, increasing HP, and increasing torque. Something the pickup engine folks can't seem to do.

One thing that is funny, is spending millions of dollars on something that might give a single digit percentage mpg gain. 1-3% mpg differences are not even verifiable in the real world. Weather, terrain, fuel quality, etc all play into it. And has been determined in many studies on the issues by those that get into it for fleets and such, like the Technology and Maintenance Council and the American Transportation Research Institute... the driver alone accounts for 30% of any appreciable fuel economy changes. That's right. Even with all the technology, the driver and how he operates the vehicle is the largest contributor to fuel economy than anything else, by several magnitudes.

Coppertone · February 2, 2015

. But they deserve more credit than the auto and pickup OEM's, in that they have substantially raised average mpg numbers on their stuff while also increasing displacement, increasing HP, and increasing torque. Something the pickup engine folks can't seem to do.

GM did this moving to the 6.2 from the 6.0 in their trucks.

Coppertone · February 2, 2015

One thing that is funny, is spending millions of dollars on something that might give a single digit percentage mpg gain. 1-3% mpg differences are not even verifiable in the real world. Weather, terrain, fuel quality, etc all play into it. And has been determined in many studies on the issues by those that get into it for fleets and such, like the Technology and Maintenance Council and the American Transportation Research Institute... the driver alone accounts for 30% of any appreciable fuel economy changes. That's right. Even with all the technology, the driver and how he operates the vehicle is the largest contributor to fuel economy than anything else, by several magnitudes.

Well sure, but if the same driver, with their same driving habits drives vehicle A that averages 20 mpg and vehicle B that averages 30 mpg; vehicle B will get better mileage than vehicle A.

Cowpie · February 2, 2015

GM did this moving to the 6.2 from the 6.0 in their trucks.

Guess you misread my post regarding this. I stated the heavy truck engine OEM's INCREASED DISPLACEMENT, and INCREASED HP AND TORQUE, and have done so to the tune of about 20-25 %. Average HP a decade ago was 400 whereas now the average is 485. The average torque a decade ago was 1550, whereas now it is 1850. All while doing these displacement and power increases, the average fuel economy for these commercial engines has gone up by well over 30%. Some as much as 50%. There is not a pickup OEM that has increased the displacement of their engine and gotten 30% better fuel economy out of the same fuel.

Your mention was going from 6.2 to 6.0, decreasing displacement, and the fuel economy has not improved by 10%, if at all. Get the idea that the pickup OEM's need to go over to the commercial folks and see what they are doing to improve their product? Imagine a 6.0L in a 2500 getting an average 25 mpg! That is where it would need to be just to keep up with what the folks on the commercial heavy trucks are doing with the fuel economy improvements they are getting.

Coppertone · February 2, 2015

I think you misread my post. I said moving to the 6.2, from the 6.0. They increased displacement, increased power, increased torque, all while being more than at least 10% more efficient.

Cowpie · February 2, 2015

Well sure, but if the same driver, with their same driving habits drives vehicle A that averages 20 mpg and vehicle B that averages 30 mpg; vehicle B will get better mileage than vehicle A.

You dearly love doing the apples to oranges comparisons don't you? My contention is that if you take similar vehicles, one with AFM, one with it disabled, and the differences in fuel economy are negligible if not downright unable to track differences in the real world. And AFM is not going to cure lousy driving techniques. And there are just too many variables out in the real world that go into fuel economy to be able to effectively track 1 and 2 tenths mpg kind of stuff. And that is all the GM is claiming the advantage of AFM does compared to a similar engine without it. There is, and never has been, any claim by GM that you are going to get 10 full mpg better with AFM, so I am not quite sure you went in for the dramatic and used a 20 mpg vs 30 mpg claim. GM has never claimed more than a 3-4% improvement, which would equate to more than .5 mpg improvement at best. And that is only verified in a controlled setting. There is no documented evidence of it in the real world averages.

Cowpie · February 2, 2015

I think you misread my post. I said moving to the 6.2, from the 6.0. They increased displacement, increased power, increased torque, all while being more than at least 10% more efficient.

You're right, I misread it. 6.2 from 6.0 is a 3% increase in displacement. I'll give you the 10% better fuel economy. But your contention is wrong anyway. They didn't go from 6.0 to 6.2, but from 6.2 to 6.0. Check out the Chevy website. The largest gas engine offering is the 6.0. So my post was correct in its assertion.

Now, commercial heavy truck engines. 13L to 15L, which is over 15% larger displacement, and at the same time between 30 and 50% better fuel economy. Think they have the process on how to build an engine down a little bit better.

Still convinced that the pickup OEM's are like poor marksmen, in that they keep shooting at the target but never can quite hit the bullseye. Like I stated, they need to have a chat with the commercial heavy engine folks and see what they are doing and maybe pick up a tip or two on how to do it with these pickups.

But this comparison is moot anyway. The original topic was regarding AFM controlled engines. the Vortec 6.2 is not AFM. It is VVT. Different deal.

Coppertone · February 2, 2015

You're right, I misread it. 6.2 from 6.0 is a 3% increase in displacement. I'll give you the 10% better fuel economy. But your contention is wrong anyway. They didn't go from 6.0 to 6.2, but from 6.2 to 6.0. Check out the Chevy website. The largest gas engine offering is the 6.0. So my post was correct in its assertion.

That's incorrect. The early 2000's "Vortex max" was a 6.0 L. 2006 - present is the 6.2. You might be thinking about the 2500 and 3500 where only the vortec 6.0 is offered. The 6.2 was never offered in those models.

Coppertone · February 2, 2015

Now, commercial heavy truck engines. 13L to 15L, which is over 15% larger displacement, and at the same time between 30 and 50% better fuel economy. Think they have the process on how to build an engine down a little bit better.

Comparing gas to diesel engines isn't really a fair comparison.

Coppertone · February 3, 2015

But this comparison is moot anyway. The original topic was regarding AFM controlled engines. the Vortec 6.2 is not AFM. It is VVT. Different deal.

The new 6.2 and has AFM and VVT.

Coppertone · February 3, 2015

And that is all the GM is claiming the advantage of AFM does compared to a similar engine without it. There is, and never has been, any claim by GM that you are going to get 10 full mpg better with AFM, so I am not quite sure you went in for the dramatic and used a 20 mpg vs 30 mpg claim. GM has never claimed more than a 3-4% improvement, which would equate to more than .5 mpg improvement at best. And that is only verified in a controlled setting. There is no documented evidence of it in the real world averages.

I was using the "20-30 mpg" as an example; not actual numbers. GM claims a 7.5% increase in fuel economy with AFM.

Cowpie · February 3, 2015

Well, it really doesn't matter, because the 6.2 is not offered in anything anymore, and the 6.0 is the gas engine for the 2500/3500. Biggest is 5.3 for the 1500. So I really am not sure why the 6.2 even is part of this discussion, as the 6.2 is not offered in any GMC or Chevrolet pickup lineup. So we are back to the 6.0L. Just can't get your mind wrapped around that idea, eh?

There are lot of marketing claims made by a host of folks in the market to sell a product. We all know that even the EPA numbers they show for MPG rarely turns out to be what the majority of folks are getting. How it plays out in the real world is altogether another matter. From all I have seen of folk's posting their mpg numbers in a myriad of forums, I have yet to see any appreciable mpg differences between AFM engines and those that have had the feature disabled by their owner. Heck my '98 2500 with a 454 big block in it put out mpg numbers that are far behind the mpg numbers of what many folks get with their newer 5.3L in a 1500. And it sure can match the mpg numbers of the 6.0 in a 2500 today. I could regularly get 16 mpg average with it, highway and town combined. Very few 6.0L in the 2500's today can beat that. Seems rather strange that a 7.4L big block from '98 can do almost as well for mpg as a 6.0 in 2015. Get the idea that the engineers are not breathing oxygen like most folks do?

sksierra · February 3, 2015

Well, it really doesn't matter, because the 6.2 is not offered in anything anymore, and the 6.0 is the gas engine for the 2500/3500. Biggest is 5.3 for the 1500. So I really am not sure why the 6.2 even is part of this discussion, as the 6.2 is not offered in any GMC or Chevrolet pickup lineup. So we are back to the 6.0L. Just can't get your mind wrapped around that idea, eh?

There are lot of marketing claims made by a host of folks in the market to sell a product. We all know that even the EPA numbers they show for MPG rarely turns out to be what the majority of folks are getting. How it plays out in the real world is altogether another matter. From all I have seen of folk's posting their mpg numbers in a myriad of forums, I have yet to see any appreciable mpg differences between AFM engines and those that have had the feature disabled by their owner. Heck my '98 2500 with a 454 big block in it put out mpg numbers that are far behind the mpg numbers of what many folks get with their newer 5.3L in a 1500. And it sure can match the mpg numbers of the 6.0 in a 2500 today. I could regularly get 16 mpg average with it, highway and town combined. Very few 6.0L in the 2500's today can beat that. Seems rather strange that a 7.4L big block from '98 can do almost as well for mpg as a 6.0 in 2015. Get the idea that the engineers are not breathing oxygen like most folks do?

Am I missing something here?

http://bit.ly/16cpe5j

LaserBlueZ71 · February 8, 2015

I was using the "20-30 mpg" as an example; not actual numbers. GM claims a 7.5% increase in fuel economy with AFM.

I call BS on GM data.

I have had my AFM disabled now for 6 months. How much fuel economy have I lost? I went from 13.9L/100KM to 14.1L/100KM average. I went from 20.32 MPG to 20.03 MPG. That is not 7.5%!!

GM developed the AFM to make the Government happy. They have to meet certain levels of emissions to meet their overall credit criteria. They design and build these systems that are mechanically unreliable or desirable, so that they can keep on building vehicles. They don't need to make a system that benefits the end user, just a system that meets the emissions criteria so they can stay in business and keep making automobiles. Don't make the mistake of thinking AFM is a good thing. Look at all the mechanical problems that have resulted from it.

The real answer is one the auto industry keeps ignoring, until only recently. Stop producing V8 engines, and then purposely disabling half of the engine 80% of the time, what's the point? Produce an engine that can give you great power, all the time, with fuel economy. It's called DIESEL! Nissan has the new 5.0 V8 Cummapart coming, Dodge has the 3.6L diesel, Ford is working on a Mini PowerJoke, that leaves GM out in the cold. Produce a Mini Duramax, stick it in a half ton, and you could easily get 30 MPG without too much effort, and it could be reliable as all heck, with tons of power available all the time, with no hokey pokey cylinder deactivation. Gasoline engines are out of date, they should have been extinct years ago. With the technology available today, everything should be diesel.

Coppertone · February 8, 2015

GM developed the AFM to make the Government happy. They have to meet certain levels of emissions to meet their overall credit criteria. They design and build these systems that are mechanically unreliable or desirable, so that they can keep on building vehicles. They don't need to make a system that benefits the end user, just a system that meets the emissions criteria so they can stay in business and keep making automobiles. Don't make the mistake of thinking AFM is a good thing. Look at all the mechanical problems that have resulted from it.

So AFM reduces emission to acceptable levels but doesn't do anything for fuel economy?