Hello - I'm installing a 3" lift on my JKU next week and I'm currently running 285/70/17 Duratracs. I'm thinking of ordering 315/70/17 Duratracs but wondered how much of a size difference there really was? Hopefully noticeable. Nobody stocks them around here so I can't see them in person. Thinking the 285's may look small with the new lift.

Also do you think I'll be okay keeping a 285 tire for spare? instead of buying five 315's?

Thanks

 

So this is a good tool - https://tiresize.com/calculator/

The 285/70/17 is 32.7 x 11.2

The 315/70/17 is 34.4 x 12.4

 

If you have an auto make sure you adjust the computer for the correct tire size so that your speedo is correct and shift points are adjusted.

R/
Will