real life MPG differences (3.08 vs 3.42)

[todayusay]

anybody have any experience with daily driver mileage differences between the two different rear end options on the yukons/tahoes...found a couple possibilities but they have the towing package that changes the rear end from 3.08 to 3.42.

 

[CND17 BURBAN]

I have a 2107 Suburban with the towing package (3.42 rear).
I drive in 2WD all the time and right now in the summer months I am getting 13L/100km (18 MPG)
My driving is mostly highway driving with about 15 min of stop and go in highway traffic.
Hope that helps a bit.
I would like to see what the difference is with out the trailer towing package gearing.

 

[sam123]

Around one mpg better on the 3.08. We have two trucks, one with and without the tow package.

 

[Blueinterceptor]

Is that mileage while towing?

I'm running a 15 burb with the towing package and regularly do 21-23 highway mileage. In running Michelin at2's 38psi

Not towing anything

 

[PAChevy]

Unless you drive mostly on flat level roads, opt for the 342. On hills the 308s will have the transmission constantly shifting and the fuel mileage is actually better with the 342s. Besides, you get the trailer brake control and 2 speed transfer case.

 

[dc968]

Unless you drive mostly on flat level roads, opt for the 342. On hills the 308s will have the transmission constantly shifting and the fuel mileage is actually better with the 342s. Besides, you get the trailer brake control and 2 speed transfer case.

You can get the 2-speed transfer case w/o the max trailer package, albeit w/the 3.08 rear

 

[cardude2000]

What's the code for max trailering? I have trailer brake control and two speed transfer but I could have sworn max trailer it was the only option I didn't order...


Sent from my iPhone using Tapatalk

 

[Tahoe14]

NHT inside glove box lid.

 

[RST Dana]

Unless you drive mostly on flat level roads, opt for the 342. On hills the 308s will have the transmission constantly shifting and the fuel mileage is actually better with the 342s. Besides, you get the trailer brake control and 2 speed transfer case.

I agree. I had a 13 with 3.08 and it was constantly changing gears unless it was a flat highway. Much better experience with 3:42.

 

[sickk23]

I agree. I had a 13 with 3.08 and it was constantly changing gears unless it was a flat highway. Much better experience with 3:42.

While I agree, would you specifically be able to tell? Your 3:42 is a 2015+ which also has more power.

3:42 is a must. But after about 75mph it’s running higher rpms than I’m use to because almost everything else I’ve driven in the last 4 years has had 8 gears. Wish the 5.3 would’ve got the 10 speed too. I’m sure it’ll trickle down eventually.

 

[RST Dana]

While I agree, would you specifically be able to tell? Your 3:42 is a 2015+ which also has more power.

3:42 is a must. But after about 75mph it’s running higher rpms than I’m use to because almost everything else I’ve driven in the last 4 years has had 8 gears. Whish the 5.3 would’ve got the 10 speed too. I’m sure it’ll trickle down eventually.

I agree I love the extra HP, having the 3.42 is almost as good as having 4.11 with my Big Blocks in the 60's!

 

[Vimes]

You ought to try it with 4.11s then. Put them in my 2015 with a speed, and it flies down low. Runs out up top though, as expected. Lost about 1.5mpg over the 3.08s. If I had it to do again, would go with 3.73s, I think. It drove like a school bus before, runs more like a car now.

 

[GTNator]

Around one mpg better on the 3.08. We have two trucks, one with and without the tow package.

Do you notice a "power" difference between the two?

 

[swathdiver]

Is that mileage while towing?

I'm running a 15 burb with the towing package and regularly do 21-23 highway mileage. In running Michelin at2's 38psi

Not towing anything

How are these tires wearing at 38 psi? Which size are you running?

 

[Blueinterceptor]

Tires look like new. 275/55/r20
Standard pressure is 35 psi. I’m not really that high

 

[sam123]

Do you notice a "power" difference between the two?

Yes. The suburban has the 3.08 and feels slower than the Yukon that has a 3.42. In my experience though, the 3.08 gets better MPG especially on the highway