Iwhat to go from 255/70/17 to a 265/70/17. I know better than to run my spare 255/70/17with a larger size tire in four wheel drive,but what about running the 255/70/17 on the rear with a265/70/17. I would only be useing 255/70/17 as a spare.Would this harm the l/s diff??

 

Different sizes on the same axle is not wise, but as a spare tire for short distances to get to a tire shop, you'll be fine.

 

I agree.