Gearing 308 VS 342 What?

gjernagan16 · October 26, 2016

Allways get the highest available (numerical) ratio possible, makes a much better driving truck.

I just got a '17 max tow 6.2 that gives it 3.42.....but wish the 3.73 was possible. but 3.73 is only 5.3 max tow

Not only just the 5.3 with 3.73, its more the 3.73's are for the 6-speed tranny while the 3.42 are the highest available with the 8 speed tranny, why they are only in the 6.2

powerhaulic · October 26, 2016

Not only just the 5.3 with 3.73, its more the 3.73's are for the 6-speed tranny while the 3.42 are the highest available with the 8 speed tranny, why they are only in the 6.2

not any more, max tow 5.3 is 3.73 w/ 8spd in slt and above

Silverado Steve · October 26, 2016

Lets see....30% less towing capability with the 3.08, negligible fuel difference cost difference for 3.42=$0...the choice is clear. I dont recall anyone wishing they got the 3.08 vs the 3.42. I love the on a flat road comparison. Come here to Colorado and tell me thete is no discernible difference unloaded. TFL did a test with the 3.08 on the Ike and they weren't too impressed.

Personally if i wanted less towing and supposed better mpg, id be driving a Colorado or Canyon instead.

07Softail · October 26, 2016

3.73's are perfect with the 6L80 and 32"tires

RT

mookdoc6 · October 26, 2016

Totally agree.

I test drove the 3.08, floored it up to about 70 mph - then I got out of the 3.08 and into an identical truck with the 3.42 and drove it the same way. No difference in acceleration whatsoever. I bought the 3.08 and have no regrets.

Us 3.08 guys can brag about how when passing, it gives an increasingly nice pull after 60mph, all the way to 100 if you let it.

blindfolded unloaded a keen dude could tell.....Put a trailer behind it with some decent weight and you will know instantly! 3.42's for the city slicker and 3.73's for the farmer.....I guess maybe 3.08's for Nebraska driving 60 miles into town? I still probably would not get it. I would sure like to know how many GM sells of that ratio is has to be 10% or about?

gjernagan16 · October 26, 2016

not any more, max tow 5.3 is 3.73 w/ 8spd in slt and above

oh sweet I didn't realize it had changed, when i built a 2017 before it was still a 6-speed with 5.3 max tow.

wuznme · October 26, 2016

not any more, max tow 5.3 is 3.73 w/ 8spd in slt and above

Highest with 8spd is 3.42's, they don't have an option any more for the 3.73's in any configuration.

powerhaulic · October 26, 2016

Highest with 8spd is 3.42's, they don't have an option any more for the 3.73's in any configuration.

I stand corrected......thought is said 8spd.....

quote from gmc spec sheet. 2017 models

Rear axle, 3.73 ratio

1 - Requires a Crew Cab or Double Cab model. Included and only available with (NHT) Max Trailering Package with (L83) 5.3L EcoTec3 V8 engine.

2 - Requires a Double Cab model. Included and only available with (NHT) Max Trailering Package with (L83) 5.3L EcoTec3 V8 engine.

wuznme · October 26, 2016

I stand corrected......thought is said 8spd.....

quote from gmc spec sheet. 2017 models

Rear axle, 3.73 ratio

1 - Requires a Crew Cab or Double Cab model. Included and only available with (NHT) Max Trailering Package with (L83) 5.3L EcoTec3 V8 engine.

2 - Requires a Double Cab model. Included and only available with (NHT) Max Trailering Package with (L83) 5.3L EcoTec3 V8 engine.

That's odd cause if try to build a 5.3 only option is 3.42's with Max Package

leddySS98 · October 27, 2016

So I've read all through this and unless I missed it some where there's no mention/opinions of the 3.23's... just 3.08, 3.42, and 3.73's... The truck configuration I built on the GMC website will come with 3.23's... Good? Bad? Ugly?

Mark Diedrich · October 27, 2016

So I've read all through this and unless I missed it some where there's no mention/opinions of the 3.23's... just 3.08, 3.42, and 3.73's... The truck configuration I built on the GMC website will come with 3.23's... Good? Bad? Ugly?

DanMan_S · October 27, 2016

So I've read all through this and unless I missed it some where there's no mention/opinions of the 3.23's... just 3.08, 3.42, and 3.73's... The truck configuration I built on the GMC website will come with 3.23's... Good? Bad? Ugly?

Split the difference between the 3.08 and 3.42. Won't accelerate as quickly as the 3.42, but don't get mileage as good as the 3.08. It largely depends on your viewpoint, it's either a good compromise, or worst of both worlds, haha.

Mark Diedrich · October 27, 2016

I briefly mentioned it on one of my posts...it will be better than the 3.08 not as good as the 3.42.

I think 3.23 (with 8 speed trans) will be comparable to the 3.42 that they had with the 6 speed transmissions. The 3.42 in the 8 speed are comparable to the 3.73 that were in the 6 speeds in 2014,2015

Are you towing much? You probably won't like it as much as a 3.42 if you are.

If your just driving the truck, then you will be fine!

Personally I wouldn't get the 3.08 even if I never pulled a trailer or hauled anything heavy.

I just don't think it does well on hills or strong head winds on a windy day, and when it's struggling, so does your mileage because your transmission is shifting all the time. And then your trans temp starts climbing too.

Just my opinion.....

Mark Diedrich · October 27, 2016

I also don't think there will be any big difference in mileage between all 3 rear ends. With a tail wind going down hill the 3.08 will probably do a little better.

With a head wind, the 3.42 because you will be able to hold your high gear better.

Imcrazy · October 27, 2016

3.23 is the same final drive ratio with the 8 speed as the 3.42 and the 6 speed I believe. Otherwise it's been a 2wd gear only with the 6 speed I think.