I have a question about tires. My friend has a 2014 Subaru Forester XT…

I have a question about tires. My friend has a 2014 Subaru Forester XT. He has one tire thats 10/32 and 3 that are 7/32. The dealer said that all 4 need to be the same because it will damage his drive train or transmission. A mechanic said it doesnt matter. Does anybody know if it matters or not? Thanks for your time 😊

Jay Smith: As I recall there are a few different AWD setups for them and depending on which one it is very possible. The viscous clutch type dont like to be constantly be splitting torque unevenly, an active clutch type could be more forgiving. There should be a spec for tire circumference variation but I do not have it… Maybe a Subie tech can chime in.

Jeremiah Bean: 3/32 of an inch wont make that much of difference. If he had 3 at 7/32 and one new one at like 20/32 that could damage some stuff. Hes fine

Dale Uvino: Thanks for the info guys!

Josh Marxen: If he has any kind of warranty on it the dealership will make a notation of it so they can refuse to warranty any repairs to the drivetrain FYI

Max Cadiente: I had a Impreza sti and , yes all 4 tires need to match on a AWD vehicle. Or you could wear out trans unevenly. Its a major pain in the ass, and extremely expensive to buy 4 new tires if you only need one. What I did when I needed just one tire was, I took the new tire to a race shop, they had a lathe and grinded down the new tire to match. They will only grind down a new tire. Any rocks will mess up their lathe. Also, they will need at least one other old tire to compare tread depth with.

Max Cadiente: Only cost me $50. I would highly recommend trying to find someone in your area to do this. Otherwise youll be risking messing up your tranny. I know a lot of guys say its close enough, but why risk it if its only $50?