with a 225 front?

Thanks

 

No as long as your rolling diameters front to rear are not off by more than half an inch.

 

i think a 245 front is the better match

 

What does this have to do with helping wear on the diff...?

 

Do you have a GT3? If your car is RWD all you really to worry about is keeping the front and rear tires pretty close to keep the ABS working properly. My guess is 295/30s are fine. Either way you can't damage anything in a RWD car since side to side diameters are perfectly matched.

AWD cars have a clutch like CENTER diff (viscous coupling) that tries to keep the front wheels rotating at approximately the same speed as the rears. If the front/rear wheels are of vastly different diameters, the viscous coupling can overheat and fail.

My personal opinions is that 30 aspect rears provide much better wheel protection due to slightly more sidewall. matching the fronts with a slightly bigger diameter (maybe 245s in the same aspect as stock) is a great idea especially on AWD cars.