I have to replace a tire on a Subaru forester 2000. The rest of the tires are in very good shape. The tire store says I need to buy 2 or a complete set because of AWD. Is that correct?
4 Answers
It all depend on how used the old tires are. The tires on a AWD system are supposed to be the same. Unless the tires are very low mileage, the minimum is to replace a pair. Some places like TireRack, will sell a new tire that has been turned down to remove the tread so it's the same size as the other three. Another option is to buy a used tire that has the same tread depth as your good tires.
The reason they recommend the same sized tire on the axle is so they don't wear out the differential. The reason they recommend the same sized tire front and back is so they don't wear out the center transfer case.
If one tire is a lot larger, it will turn less revolutions per mile. It would be like the car is always turning in a large circle.
Different tread patterns can also cause differential issues due to differences in rolling resistance, in addition to the fact that no two model of tire are truly the same in size.
