Would 35x12.50 R15 tires fit 15x8 4.0 backspace?? If anyone has this setup..how do you like it ? Thanks!

 

Your big issue on 15" rims is NOT the tire...its the rim hitting the brake calipers...many needed to grind/clearance the calipers to make the rim clear the brakes.

As far as the BS goes...if the rim clears, 4.75" BS even works for 12.5" wide tires....depending on the EXACT 15" rim though, its trial and error, as the rim itself generally is too small to avoid needing some extra work to make it work as well as say a 16" or larger rim, etc....so, less grinding = more BS needed to be taken off, etc.

 

Do you have the same issue with 16" rims, or do they squeek by?

 

16" should be fine. Some X models come stock with 16" steel wheels - and I believe those wheels even have the standard 6.25" BS as do all the other "premium" JK wheels.