[Number 3]

Originally Posted by Martinjlm

Discretion of the Exec. Chief Engineer, with guidance from the people who advise on f/e/ targets their specific vehicle needs to achieve to help balance GM portfolio. Corvette is lower volume than Camaro and therefore less overall impact on CAFE.

There could be other factors, but that's what comes to mind.

I remember Tadge saying one time he wanted the car to run like crap in ECO mode so that no one would ever use it. Plus I don't think the Stingray has a GG tax for either auto or manual. CAFE is run on what is base. If you make a selectable ECO mode you can't use it in the test. It just becomes something the customer can choose. But if you need it for CAFE or avoiding GG tax it has to be standard and not selectable or something the customer can turn off.

But in the C6, due to the tube running from the engine to the trans it was judged non-commercial. I believe changing the tube to steel in the C7 was what fixed that.

Originally Posted by mekirk2

I looked for it and didnt see it on my SS sticker....

Shouldn't be there as that is the reason for AFM is the GG tax avoidance.

Originally Posted by Stig eh

AGREED STIG EH

GG tax was on my SS sedan which did not have AFM. $1800 I think.

Invisible in my new LaCrosse, btw.

[JCunningham]

AFM in my 2017 5.3l silverado is not felt or heard either. in my 08 and 12 silverados it was very noticeable and took 2mpg from the trucks. 4cyl couldnt keep the truck moving at 55mph so it would just stutter and go back into 8cyl. got a custom tune sct and told the tuner to just turn off afm and i gained 2mpg in both 5.3l 08 and 12 silverados.

[Martinjlm]

Originally Posted by Number 3

I remember Tadge saying one time he wanted the car to run like crap in ECO mode so that no one would ever use it. Plus I don't think the Stingray has a GG tax for either auto or manual. CAFE is run on what is base. If you make a selectable ECO mode you can't use it in the test. It just becomes something the customer can choose. But if you need it for CAFE or avoiding GG tax it has to be standard and not selectable or something the customer can turn off.....

Mostly true, but there is this thing called "off-cycle credits" that blurs the picture a little. Best example of off-cycle credits is E85. Automakers can get credit for having E85 on vehicles even though a lot of (most?) owners never use E85. Car companies have the option of demonstrating some level of usage and then get partial credit. Stop Start does have a path to partial CAFE credit for systems that have a turn off switch. It is not used on the test, thus the name "off-cycle", but automakers can still get some level of credit for having the technology if they can demonstrate that customers are using it.

[Opus13]

I like getting 32mpg on the highway and still be able to drop the hammer on a M3. No problems, noises or vibrations here.

[Number 3]

Originally Posted by Martinjlm

Mostly true, but there is this thing called "off-cycle credits" that blurs the picture a little. Best example of off-cycle credits is E85. Automakers can get credit for having E85 on vehicles even though a lot of (most?) owners never use E85. Car companies have the option of demonstrating some level of usage and then get partial credit. Stop Start does have a path to partial CAFE credit for systems that have a turn off switch. It is not used on the test, thus the name "off-cycle", but automakers can still get some level of credit for having the technology if they can demonstrate that customers are using it.

Agree it's not cut and dry.

Agreed, but there is a lot of grey in showing it is used. There is a reason the ATS has an on off switch for start stop and the LaCrosse doesn't.

But from what I've experienced, putting the LaCrosse in manual shift mode defeats start stop LaCrosse with paddle shifters.......who would have thunk it.

I have no experience in how E85 was credited.

[Martinjlm]

Originally Posted by Number 3

Agree it's not cut and dry.

Agreed, but there is a lot of grey in showing it is used. There is a reason the ATS has an on off switch for start stop and the LaCrosse doesn't.

But from what I've experienced, putting the LaCrosse in manual shift mode defeats start stop LaCrosse with paddle shifters.......who would have thunk it.

I have no experience in how E85 was credited.

Yes, there is a reason. Cadillac INSISTED on it. It was a VERY heated debate that I and my team were heavily involved in. We had to provide leadership with a clear forecast of who would be coming to the entry lux/ mid lux market with Stop Start and which of those would have the opportunity to switch it off. BMW not only provides an off-switch, they pair the off-switch with the engine start button so you can literally start your car and turn off Stop Start at nearly the exact same time.

As for E85, it's no surprise you wouldn't know how E85 is counted / measured. It was highly political. By political I mean congressional involvement beyond reason. Corn farmer lobbies, oil lobbies, Senators from states A and B vs Senators from states C and D. What is in place is an irrational compromise that I don't really understand very well either.

[FENDER1]

I have a 2017 Camaro SS and have only recently noticed that it now switches to 4 Cylinder Mode while driving through my neighborhood at 20 - 25 mph. I would have sworn that it never switched over unless we were on the open road. Is this normal? (Note: I leave it in Sport mode with the exhaust set to Track. Not sure if this makes any difference.) Thanks!

[Martinjlm]

Originally Posted by FENDER1

I have a 2017 Camaro SS and have only recently noticed that it now switches to 4 Cylinder Mode while driving through my neighborhood at 20 - 25 mph. I would have sworn that it never switched over unless we were on the open road. Is this normal? (Note: I leave it in Sport mode with the exhaust set to Track. Not sure if this makes any difference.) Thanks!

It’s normal. I am mostly in Sport with exhaust set to either Sport or Track (can’t remember and think they may be the same anyway).

[lt4camaro]

All Chevrolet had to do was give us a choice "on or off" or eco mode only for AFM

AFM is not good for the auto trans or the converter, AFM requires heavy limited RPM lifters, AFM doesn't increase fuel mileage enough to consider it a must.

[HackSaw]

with the ss if you have a auto trans doesnt putting the shifter in manual mode keep the motor in v8 all all times

[mdhopt36]

James, you didn't post what the "research" revealed in fuel savings. Care to post that?

[Martinjlm]

Originally Posted by mdhopt36

James, you didn't post what the "research" revealed in fuel savings. Care to post that?

Which of my posts are you referring to? (I'm too lazy to go back and look). Typically, AFM can deliver around 5 - 7% fuel economy improvement on the EPA test cycle. I've seen some estimates in the 10% range but can't recall who's they were. Based on temperature, terrain, driving style, etc your mileage my vary.

[Martinjlm]

Originally Posted by HackSaw

with the ss if you have a auto trans doesnt putting the shifter in manual mode keep the motor in v8 all all times

Good question. I think it might. I'll have to try that sometime.

[mdhopt36]

Close enough James, thanks.
My limited experience so far, is in long hills, I like to put it in manual mode, and drop it to 7th when pulling the hill, which keeps the tach at around 1500rpm's- instead of down around 1100 in 8th.
So far, i notice absolutely no mileage difference, and it doesn't drop 4 cylinders during the climb.
I remember coming across something you plug into the diagnostic, and it cancels AFM.
Just pull it out when going to the dealer for work----? Sounds simple enough, doesn't alter any of the control module programming.