Regear after changing to 315/70/17?

[57buick]

No way you’re at 16 mpg

I have been without a roof rack for a couple months cuz I sold mine but my new SSO roof rack just arrived. We will see if that has any difference in mileage

 

[skratchd]

Your motor must be screaming down the highway. I have 4.56's and it sits around 3000rpm at 70mph. I will be installing 315/70/17's tomorrow and I hope that helps.

 

[Bumbo]

I run a 32.1” tire on stock gears and I can tell the difference. It’s still drivable, and I can get away without doing anything, but I can still tell. If I move up to a 33” tire I’ll go with a 4.56 gear.

34.4” tire on stock gears… personally I would be looking to re-gear. That’s a whole lot of tire and these trucks already feel like they could use a little gearing. It must feel like you are lugging the motor or often times in the wrong gear. That said, I haven’t driven with an almost 35” tire.