How much difference will the Mpg change with tire change ?

47metro · October 15, 2016

My truck has the 245/75/17 tires in it and I'm thinking of upgrading to the 18" wheels and tires to get a better looking wheel and a higher load range. Has anyone made this change ? What did it do to the Mpg?

Thanks in advance for sharing.

Anthony

BigBadSierra · October 15, 2016

It will come down to how aggressive the tread is and the weight difference.

If your going to an agreesive tread like KO or Duratac your millage will drop.

I took my SRA's off and put on Goodyear Duratrac's and saw a 1/12 mile per gallon drop but the added traction was worth it.

Cowpie · October 16, 2016

And not only the tread design, but the compounds the tire is made from. It is a total package. There are some AT type tires that get some respectable mpg numbers on par with some poorly design non AT tires.

Colossus · October 16, 2016

1-2 MPG if you go 1 size up.

47metro · October 17, 2016

Thanks ! I was wondering if the folks who have 20" wheels and tires get less mpg than those of us who have the shorter 245/75/17 tire and wheel combo do.

I was trying to make sure I stayed under the height of the 265/65/20 tires are. Is there a difference in the gas mileage by tire and wheel size?

Cowpie · November 1, 2016

Can be. A taller tire sidewall has a negative effect on fuel economy in most cases. How much, that is subjective. Mine came with 265/70R18 Michelin LTX AT2's and I went one size up with 275/70R18 BFG KO2's and haven't seen a significant change in fuel economy. In the less than 1 mpg range. I would have expected more since the KO2's are more aggressive. Tire design and tread compounds, if done right, can make the changes not that bad. On both tires, I typically run 50-55 psi in them when empty or lightly loaded as opposed to the stock 60 front 70 rear OEM recommendation. That actually helped mpg a little. I attribute that to less wheel hop when empty and the anti slip electronics having to micro adjust all the time to compensate. If I know I will be loading the pickup heavy, I air them up. And the ride is sooo much better when psi is lowered when empty.