nail..replacing one tire on awd car?
 

i have a nail very close to the sidewall of the tire that cannot be repaired. the tire shop suggested i replace one tire with a new tire. Since my car is AWD, won't this throw off the AWD system as the diameter will be different than the other three tires? (i have 30000KM on the tires currently

instead of replacing all four tires, does anyone know anywhere reputable that does tire shaving to match the tread depth?

what kinda awd is it?

for the most part it will throw it off, but there's certain max and min limits for that system that the manufacturer has/knows.

give them a call first and see if its ok.

First see how much tread is left on your 3 tires first.. with 30k, the tires are towards second half their lives anyways. If it is a softer tire compound, it makes more sense to replace all 4 now.

How about swapping 2 new tires onto a AWD Subaru Outback 98 ?
& re-using 2 old tires with 70% thread left
Work ? or Don't do it ??
Thanks & Appreciated

1st time AWD car owner

I think the specs for a Subaru is no more than roughly 2/32 difference in tread between all 4 tires.

The actual specs require you to measure the circumference of the tires and that it be no more than 1/4" difference.

If they are oem tires then they are most likely close to done at 30,000 kms, I would not recommend 1 new tire. If your trying to save money hunt around for a used tire in the same shape as the other 3.
If the hole is close to the sidewall then it may still be repairable with a mushroom plug or liquid plug patch, if its on the sidewall or you've run on it flat, its done.

If your awd car uses a limited slip viscous coupler then replacing just one tire will drastically reduce the life span of your viscous coupler. The tire shop should know that and thus if your tire was really beyond repair they would have recommended a whole new set of tires.
Sounds fishy to me. If you like bring the tire by my shop and I can offer you a second opinion, possibly a repair solution.