Mileage impact when upping tire size - 6.0 4x4

December 20, 2011

Guys,

I have a 2001 2500HD 6.0L crew cab short bed 4x4. Right now I have 276-75-16 street tires on it. I'd like to go up to 285-75-16 BFG All-Terrains or some other similar A/T but I need to guestimate how bad this will hit my gas mileage. Has anyone gone up a size and if so what was your experience?

Thanks,

Stevens03 · December 20, 2011

You'll take about a 1-2 mpg hit on mileage. Keep in mind, if you don't program the PCM for the larger tire, your speedo, mileage, and shift points will be off a little reporting your mileage wrong. If you get some sort of programmer, you'll have a better change staying close to the same mileage you have now.

Either way, you won't see more than 1-2 mpg less.

Mckenzie · December 20, 2011

I got an 01 with the 5.3 and with 285/75/16 MT's i get about 11-12 city, and maybe 14ish when on the interstate driving like a granny. You'll definitely take a noticeable hit, but it's definitely worth it

nbuchanan · December 21, 2011

I have a 2003 2500HD with a 6.0 with 285/75/16s and I get around 12-14 on average. If I drive long range down the highway at 60 mph I will get around 15.5. But its 6.0, they suck gas anyway you look at it!

unclemark · December 22, 2011

I wouldnt worry to much about the MPG with the 6.0. I have an 01' 6.0 4x4 too and I dont think its possible to get any worse than we already do.

btrbbt · December 25, 2011

I have a 2010 2500hd 4x4. 6 liter, 3.73 gear, wimpy 245 75 R16 highway tires, 6 speed auto, no AFM, and get 14.5 mpg with 70% highway driving. I am going to lift it 2" and goto 285 75 r16 Duratracs in two weeks... I will average another 6 tanks of fuel after that. I assume the 10% taller all terrain tire and higher profile truck will have higher rolling resistance and higher aerodynamic hp demand over 50 mph and will drop to at least 13 mpg. The weather is getting colder too which is always a minus for me. My HD is my hobby so 13 mpg to look good versus 14.5 and wishing it looked better is worth it!

nbuchanan · December 25, 2011

My HD is my hobby so 13 mpg to look good versus 14.5 and wishing it looked better is worth it!

I like this quote!

btrbbt · January 14, 2012

Well I went from the 30" 245 75 R16 to the 33" 285 75 R16. Truck looks great but now I gotta average some fuel ups and figure out miles per gallon. The tire is 10% larger in diameter and I know I need to figure old versus new diameter based on rolling radii. Its 10% change to the odometer so I am calculating that in because I did not get my speedometer/odometer calibrated. Anyways for fuel calculation I will add 10% to the reported trip odometer for each tank. This is important because it makes the fuel mileage better by 10%! Sweet corn niblets.... its not 12 mpg it is a whopping 13.2 mpg after adding that 10%. I am practically making gasoline!