can I change my 17'' tires and rims form my 2012 jeep and go to 18'' tires and rims from a 2014 jeep both tires are 255/70rs
Yes, if you want to keep the tires the same outer diameter and width, so your speedometer doesn't read incorrectly and you don't have any clearance issues, you could go with 255/65R18 tires
The 255/70R18 tires would be 1" larger in diameter than the 255/70R17, which would cause your speedometer to read 3% slower than your actual speed. If you don't care about that though, the 2014 rims would be perfectly interchangeable, both are 5x5 bolt pattern.
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