Looking at 6.2

JimCost2014 · July 20, 2017

Placebo...

6l80 1st gear ratio: 4.03 x 3.42 = 13.78

8l90 1st gear ratio: 4.56 x 3.23 = 14.73

Kind of, biggest difference is the tuning of the transmissions, the 6 speed will hold a gear (wind out) longer than the 8 speed. 8 speed is programed for max fuel mileage, so it shifts fast, then gets confused, downshifts hard and wanders to try to find a happy gear. Between the two, it takes a lot more of WOT on the 8 speed to go at the same clip as the 6 speed. My personal experience with two almost (99.9%) identical trucks.

truckguy82 · July 21, 2017

Kind of, biggest difference is the tuning of the transmissions, the 6 speed will hold a gear (wind out) longer than the 8 speed. 8 speed is programed for max fuel mileage, so it shifts fast, then gets confused, downshifts hard and wanders to try to find a happy gear. Between the two, it takes a lot more of WOT on the 8 speed to go at the same clip as the 6 speed. My personal experience with two almost (99.9%) identical trucks.

8l90 keeps throttle open during the shift

6l80 temporarily cuts power during the shift

8l90 is a really nice trans, not sure why it doesn't perform all that much better in the truck in comparison to the 6speed.

If you drive a camaro or vette with the 6l80, and then the same with an 8l90, you'd be amazed at how much better the 8l90 is. You definitely feel the difference with that "power through shift", and the 1-2 shift especially just feels awesome.

T1Kaiju · July 21, 2017

Well guys, gonna stay put. Truck rides is great on smooth roads, but my drive home from workt is full of highway construction, and man this loaner bounces a lot. It also isnt as stable on the bumps as my avy. So I guess I can spill the beans on the dealer - Hiley in fort worth. One I wanted was maroon with the roof and nav for 42.5. They got quite a few lower slt 6.2. Good luck!

Sent from my SM-G950U using Tapatalk

L86 All Terrain · July 21, 2017

Kind of, biggest difference is the tuning of the transmissions, the 6 speed will hold a gear (wind out) longer than the 8 speed. 8 speed is programed for max fuel mileage, so it shifts fast, then gets confused, downshifts hard and wanders to try to find a happy gear. Between the two, it takes a lot more of WOT on the 8 speed to go at the same clip as the 6 speed. My personal experience with two almost (99.9%) identical trucks.

I have a 2015 6.2 8spd and a 2014 5.3L 6spd and there is no comparison on which trans is smoother and quicker shifting. Even my first 6L80 in 2010 was twice as good as the set up in these trucks. The tuning is way off on the 6 spd mine anyway, clunky reverse to drive, random hard up and down shifts every now and again. The 8L90 in my 15 is smooth as silk in comparison. Only time it will do anything funky is if you are all over the place with the fuel pedal when it about to shift. People still drive it like the old 4spd autos.

michigan2500hd · July 21, 2017

I have a 2015 6.2 8spd and a 2014 5.3L 6spd and there is no comparison on which trans is smoother and quicker shifting. Even my first 6L80 in 2010 was twice as good as the set up in these trucks. The tuning is way off on the 6 spd mine anyway, clunky reverse to drive, random hard up and down shifts every now and again. The 8L90 in my 15 is smooth as silk in comparison. Only time it will do anything funky is if you are all over the place with the fuel pedal when it about to shift. People still drive it like the old 4spd autos.

I came to the conclusion that part of the shifting issue is the way I'm driving it. I'm used to lifting the foot ever so slightly to help shift like I did with the 4 speed and even the 6 speed somewhat.

However I've made it a point to put steady, even pressure on the gas pedal and unless I'm looking for somewhat quick acceleration it still does a bunch of tiny surges.

I feel I'm very in tune to what's going on when I drive a vehicle so I'm sure I notice things that others don't. You know the kind of people I'm taking about..

Sent from my E6810 using Tapatalk

JimCost2014 · July 21, 2017

8l90 keeps throttle open during the shift

6l80 temporarily cuts power during the shift

8l90 is a really nice trans, not sure why it doesn't perform all that much better in the truck in comparison to the 6speed.

If you drive a camaro or vette with the 6l80, and then the same with an 8l90, you'd be amazed at how much better the 8l90 is. You definitely feel the difference with that "power through shift", and the 1-2 shift especially just feels awesome.

Took a long weekend to San Francisco and rented a 17 Camaro SS convertible. "Same" drivetrain as my truck, no comparison, the Camaro was so much smoother, no hard shifts, clunks or wandering, or the weird downshifts. For the most part my truck's 8 speed has been good, compared to some on here, but the Camaro really made me scratch my head as to why it was so different feeling in a good way.

truckguy82 · July 21, 2017

Took a long weekend to San Francisco and rented a 17 Camaro SS convertible. "Same" drivetrain as my truck, no comparison, the Camaro was so much smoother, no hard shifts, clunks or wandering, or the weird downshifts. For the most part my truck's 8 speed has been good, compared to some on here, but the Camaro really made me scratch my head as to why it was so different feeling in a good way.

Thats what I did lol, rented a '16 SS

Amazing thats the same drivetrain.

The sound it makes and the trans.

Freaking riot isn't it? So fast

JimCost2014 · July 21, 2017

I have a 2015 6.2 8spd and a 2014 5.3L 6spd and there is no comparison on which trans is smoother and quicker shifting. Even my first 6L80 in 2010 was twice as good as the set up in these trucks. The tuning is way off on the 6 spd mine anyway, clunky reverse to drive, random hard up and down shifts every now and again. The 8L90 in my 15 is smooth as silk in comparison. Only time it will do anything funky is if you are all over the place with the fuel pedal when it about to shift. People still drive it like the old 4spd autos.

I liked how my 14 6.2 6speed worked together, it was pretty smooth. My 16 6.2 8speed just feels a little more sluggish on take off. Boy, I really have gotten this topic way off course.

JimCost2014 · July 21, 2017

Thats what I did lol, rented a '16 SS

Amazing thats the same drivetrain.

The sound it makes and the trans.

Freaking riot isn't it? So fast

Yes it was, if I am ever in the market for a car, that would be at the top of my choices.

truckguy82 · July 21, 2017

Yes it was, if I am ever in the market for a car, that would be at the top of my choices.

My favorite part about it, which you probably didn't get to experience, is that after 24k miles, a crack rim, pulling to one side, a noisy differential, light body damage, all indicators of it getting the living shit beat out of it.......there were no rattles at all in the interior or suspension and the thing was still as solid as a block of granite.

JimCost2014 · July 21, 2017

My favorite part about it, which you probably didn't get to experience, is that after 24k miles, a crack rim, pulling to one side, a noisy differential, light body damage, all indicators of it getting the living shit beat out of it.......there were no rattles at all in the interior or suspension and the thing was still as solid as a block of granite.

7 miles on the 17, only thing we did not like about was we could not figure out to get the top down for a day. Strange set up with a "mat" in the trunk that has to be moved in a certain way, after that, fast drop top cruising!!!!

T1Kaiju · July 24, 2017

Finally got my avy back today after 5 days in the 4.3 2017 LT. I was all set to go to Hiley as no one has grabbed the 6.2 crimson yet, but about 15 seconds in my old truck, and I decided ride > electronics. That damn avy is buddah. Now im gonna focus on a tune with a supercharger in my future. Yall get those 6.2s before they sell out...

Sent from my SM-T350 using Tapatalk

powerhaulic · July 25, 2017

17k on my '17 6.2, no regrets........

Had an '11 6.2 6spd before, loved it but this truck rocks.

Linecapt · July 25, 2017

Go for it. Had a 5.3 in my '13 Silverado LTZ and now the 6.2 in my '16 Sierra LTZ dbl cab and love it. Have a 6.0 in the Corvette C6 so wanted to keep the big engines and power from either vehicle I'm driving. Besides the price difference in fuel octane price, the MPG's are great. 4 hour highway drive in tandem with the brother in law in his '16 Tundra and 5.7L, I beat him in the MPG comparison by 2.+ MPG. He thought my 6.2 would be the detriment but the active fuel management and 8 speed auto were evidently the winning combo.