3.08 vs 3.43 - what's better?

[Easy Runnin]

Considering a 2wd extened cab with the 5.3 engine and sport package. It comes with either a 3.08 or a 3.43 rear axle ratio. What's the difference? I figure the 3.08 is more economical and the 3.43 allows me to tow more. Is it that simple? How much of a difference in MPG? I don't think I'll ever tow more that 6,700 pounds, which is the limit on the 3.08. Should I consider the 3.43?

 

Thanks for the replys

[MikeNH]

I doubt you'll see much of a savings with the 3.08s. I'd go with the 3.42s to get more power to the ground. As it is I think these trucks are geared too tall for lower highway speeds so 3.08s will only worsen that.

[RyanbabZ71]

There is no gear offering in a 3.43 for gm (I assume you mean 3.42). GM offers either 3.08, 3.42, 3.73, or 4.10

 

If you are going to do any towing or haluing or even change tire sizes go with the 3.42's

[travis73]

Agreed,3.42 gearing is the best way to go.

[vkjohnson]

Haven't heard of too many with the 3.08. Only reason I have it is because every other option I wanted was included with the truck and wasn't ever going to do any towing other than a lawn mower trailer once in a while. That said, my next one will have a 3.42. At highway speeds it's great and could probably get 21 or 22 mpg if I kept my dang lead foot off the gas. As high as 85 mph I am still under 2,000 rpms. Stop and go driving is when it fails me. 1st ends up geared way to high for any smooth accelerating from a stop IMO. I REALLY have to feather the gas. Beyond that I think it operates as smooth as the other rear ends. ....and +1 on the tire size. I can't imagine how bad a 3.08 would be with bigger tire size

[SouthCo]

3.42

[EcWrestlr]

I have the 3.08 and I upgraded the tires to a 285/65/18 and the thing is a pig. I pull a boat every now and again that is somewhere around the max tow rating (6500 lbs) and it pulls it, but would pull it much better if I had the 3.42's. I'm considering a programmer to try and get as much out of the package I have without changing too much. It seems everyone I ask about switching the gears to a 3.73 is against it with the 5.3 litre engine. Not really sure why........

[Gurrzt]

Get the 3.42:1 gears, the 3.08:1 gears won't let you get out of your own way.

 

I have 3.42:1 gears in my Yukon Denali, coupled to the 6.2L, and I am still averaging 14.8mpg.

[jerry50]

i have a 07 sierra nbs with g80 locker and 4:10 gears they haven't offered them for a few years now,cause there doing gearing more so with tranny,all i know is i get 15mpg city and 19 highway with foot out of it but if floor it i can fry the tire off of it

[Doug_Scott]

I have a feeling the OP meant 3.23, not 3.43. He says it is a 2wd truck. Assuming he is meaning new, get the 3.23 with the 5.3. 5.3 has the six speed trans. I think the 3.08 would end up being disappointing in drivability after a few months.

[Gurrzt]

The rpo code for 3.23:1 is "GU5", and I do not believe it is available for the GM trucks.

[Doug_Scott]

The rpo code for 3.23:1 is "GU5", and I do not believe it is available for the GM trucks.

 

 

It is available, but with the 4.8 or 4.3.

[Easy Runnin]

It's 3.08 vs 3.42. I just test drove both without knowing which had which. And after the test drive, my guess was incorrect. I went with the 3.08 hoping for better mileage.

[Wires]

You'll probably find the 3.42's will end up giving better mileage overall than the 3.08's. The 3.08's will give better mileage in optimum conditions (flat ground, no head winds, etc). As soon as the "real world" kicks in, the truck tends to labor more, and mileage suffers.

 

[BlackZ71Silverado]

It's 3.08 vs 3.42. I just test drove both without knowing which had which. And after the test drive, my guess was incorrect. I went with the 3.08 hoping for better mileage.

 

 

Sorry but if better MPG was what you were looking for you made a mistake. The 3.08's will have to work harder to maintain the rpm's if you drive anywhere other than perfectly level ground.