I tried searching, saw some threads on the subject, but no one had an answer. I'm wondering if having a newer tire on the rear (not replacing all 4 for a stupid nail, and they only had a few thousand miles on them) would mess up the diff or driving on one 225/50 and a 245/45 would harm it. I know this was a big deal on my old audi with a torsen center.

In the end I'll probably just put the new tire up front and not drive it with the 2 different tires that are on it now, but I'm just kinda curious.

 

The owners manual (or maybe it was the FSM) warns against different sized tires on the rear axle due to the Torsen. Excess heat will be built up in the diff with any significant difference in revs per mile on the two sides.

 

why don't you just get the right sized tire? you're just pissing away $$ buying a tire in the wrong size and it is going to drive like ****.

 

I wouldn't do it. Even if you put it up front, the car will pull to one direction, and handling will be unpredictable.


If you feel the need to get a different size, buy two.

-s-

 

I must not have explained it well. It's sitting on one of my 245/45 race tires in the garage because I saw the screw in the street tire while swapping them, and I haven't been driving it. Just sucks because the weather is perfect and I want to drive it. I bought a new street tire of the same size/brand/type as the other streets, but it will be slightly bigger since it's brand new vs like 3k miles.

I'm getting the street tire mounted tomorrow anyway. It was more of a curiosity thing. I'll probably put it on the front to avoid any diff issues.

 

IMO, you will not have any problems with a 3k mile difference in otherwise identical tires. I have had to replace a single tire twice since owning the car and haven't experienced any issues.

 

^^ What he said. 3k miles is nothing on a tire,...unless you are the type that likes to burn away $$$ by doing burnouts and dognouts and stuff. then you may have a bigger difference in tires but still not enough to do any harm. just **** you off cause you have 1 bald rear and 1 new(er).