Gas mileage on AT4 with 6.2 and 35’s

Cjb1979 · December 27, 2020

I have done a ton of reading, but cannot seem to get an idea of what to expect for fuel mileage for a crew cab AT4 with a 6.2 and 35” tires. Still trying to decide between a 34 (275/65/20) or a 35/11.5/20, either size would be a Nitto Ridge Grappler. I ran the 275/65/20 on my Silverado with the 5.3/8speed combo and mileage wasn’t much different from stock. So what does everyone say?

romclean1 · December 27, 2020

I’m getting about 16.5ish with 285/65’s (34.6x11.2) average. About 12.5 driving like my inner 16yr old. 18.5 on the highway driving like my dad did.

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Rob Mugs · December 28, 2020

18 or so highway

1-10 on side streets

cfwilli3 · January 5, 2021

I am getting 16 on the highway and 12 in town on 35x12.5x20 Nitto Trail Grapplers. Crew cab AT4 with a 2" leveling kit.

FWaT4 · January 5, 2021

Logged 17.8 today from Fort Worth to San Antonio- roughly 275 miles- going 75-80 and about 10 minutes of bumper to bumper in Austin. On average with my city driving added in I get around 15. Now when I drive 250 up to Oklahoma through the hills, I usually get around 16 mpg doing 75-80. I dont ever use the cruise control either, truck always feels like it is hunting to get back to speed through the hills, slams into gear then revs up to 2500 plus rpm to get there. I prefer the smoother ride so I just give it a little gas as needed.

AT4 with 6.2 on Nitto Ridge 35 * 11.50* 20, 1'; level and muffler deleted.

Edited January 5, 2021 by FWaT4

J2Jones · January 5, 2021

On 12/27/2020 at 5:50 PM, romclean1 said:

I’m getting about 16.5ish with 285/65’s (34.6x11.2) average. About 12.5 driving like my inner 16yr old. 18.5 on the highway driving like my dad did.

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I get about the same with my 6.2 AT4 35x11.50 NRG's, no lift. Has GM performance intake and Borla S-Type cat-back. I actually find the MPG to be quite temperature sensitive. My MPG seems to be at least 1 MPG lower when it's cold and that's in NC. Hate to think what the temps in farther north would do to MPG. Anyone else notice this?