[Kracka]

Originally Posted by matt d.

do you mean width or circumference? You can run different widths (though i don't know why on a street car) but the tires must be the same circumference all around. If you have different sizes of tires it will cause excessive wear on the differentials.

Also, being close isn't good enough. That's why you need to replace all four tires on an awd car even if one is bad, or have the tread on the new one shaved down to the same height as the other three.

+1