Tires: tire compatibility, 2007 subaru impreza, subaru impreza

Question
My son drives a 2007 Subaru Impreza with Bridgestone Potenza RE92s in size 205/55R16 with a V rating.  On line, Firestone advertises a Potenza G019 in the same size and speed rating for about $100 less than the RE92.  They claim he can't use the G019s because his transfer case will get messed up.  I thought as long as the size, speed rating were the same it didn't matter.

Answer
Bob,

Subaru's are known for their sensitivity to tire diameter.  The safest thing is to have 4 of the same tire at the same state of wear - this means regular rotation.  If you follow that, you will always have a case with Subaru if the transfer case fails.

From that point forward, everything else represents a risk of failure of the transfer case - and that means Subaru won't cover it.

The next thing would be a pair of tires that is otherwise identical to the pair that are going to be kept on the car.  The problem here is 2 fold - state of wear and the difference in the tire itself.  To my mind, it is the state of wear that is the bigger of the 2 problems.

Also to my mind, if the vehicle came with V rated tires, then anything other than a V rated tire represents a risk - and especially do for S or T rated tires.  This includes the purchase of 4 of the same tire, and is a major problem for tires purcahsed in pairs.

So if you are thinking about buying a pair of tires - I think you ought not to do that.

But if you are buying 4 - what you've told me is OK.