How to not tune a 4l60

[Marky Dissod]

... still in the 'no idea about tuning' category ... where do I start?

PCM Performance won't take phone calls, but you can email him all your questions, his answers are very thorough.
BlackBear Performance also comes highly recommended here.

Either way, just explain what you want & don't want as best you can.
If you want me to help you make better sense of anything, just ask -
I kinda want to see the whole world get tuned ...

 

[Mudsport96]

Fixed it for you. Pass this on to EVERYONE you possibly can:
EVERY vehicle sold in America with a V8 was woefully under-geared to improve CAFE MpG scores (not just GM).
If your old 'bubba didn't have 4.10, it was under-geared.

In ANY / EVERY GMT900, 3.42 should have been the MINIMUM axle gear - NOT 3.08.
GM's OE early upshifts and late downshifts would be even earlier and later with 3.73!
(unless it was a 2500 or 3500, which are not under CAFE MpG test score scrutiny).
Even those with 6L90s & 2500 / 3500 are held back a bit by GM's OE 'tune',
but not as much as 1500-type vehicles.

We're outnumbered about 100:1 by those who either have no clue about tuning,
or are uninformed enough to be against it because they THINK they're informed.

Yeah GM blundered that, but part of it is trying to blanket tune for the entire buying public. Good engineer friend of mine did a transmission only tune with HPT on his '19 1500 with the 5.3. Took him 2 weeks of tweaking, but he has picked up 2 mpg overall. The trick was not lugging shifts, and keeping it out of 1st unless towing and 6th until 65mph.

 

[Marky Dissod]

GM blundered that, but part of it is trying to blanket tune for the entire buying public.

You forgot to mention how CAFE MpG scores affect transmission behavior.

Good engineer friend of mine did a transmission only tune with HPT on his '19 1500 with the 5.3L.
Took him 2 weeks of tweaking, but he has picked up 2mpg overall. Trick was not lugging shifts, and keeping it out of 1st unless towing and 6th until 65mph.

2 weeks of tweaking was definitely worth it then.

 

[Mudsport96]

You forgot to mention how CAFE MpG scores affect transmission behavior.2 weeks of tweaking was definitely worth it then.

I didn't for the fact that tuning got the mpg up. So if the Cafe standard was the sole reason I would think they would have done what he did. I also reserve the right to be wrong about that.

 

[Marky Dissod]

I didn't for the fact that tuning got the MpG up. So if the CAFE standard was the sole reason, I would think they would have done what he did. I also reserve the right to be wrong about that.

Instead of 'arguing' - no urge to beef with anyone ...

The CAFE MpG test score standard is clearly NOT how your good engineer friend drives.
For that matter, most people do not drive similarly to the CAFE MpG test patterns.
That's why very few people very rarely achieve the city MpG estimate.
If the city test pattern was a day in Manhattan rush hour, on the other hand ...

The highway estimate is easier for normal people to achieve often, if they try.

I for one would love to see a comparison of your good engineer friend's altered shift pattern,
and compare it to GM OE to see how HE gained MpG.

 

[Mudsport96]

Instead of 'arguing' - no urge to beef with anyone ...

The CAFE MpG test score standard is clearly NOT how your good engineer friend drives.
For that matter, most people do not drive similarly to the CAFE MpG test patterns.
That's why very few people very rarely achieve the city MpG estimate.
If the city test pattern was a day in Manhattan rush hour, on the other hand ...

The highway estimate is easier for normal people to achieve often, if they try.

I for one would love to see a comparison of your good engineer friend's altered shift pattern,
and compare it to GM OE to see how HE gained MpG.

I'll see if I can get a couple screenshots. He said the biggest thing was holding gears longer, but not too long to keep the engine rpm up. And he had alot of hunting between 5th and 6th that he tuned out with delaying that shift quite a bit.