Damaged tire -Do I have to replace all four?

[TonyG]

I put on four new Pirelli P zero Nero M+S about a year ago. They have about 25k highway miles on them and have a lot of meat left. I got a nail in one, and put a plug in it (it was too close to the edge for a patch). It held up pretty well for a month, but now developed a slow leak.

If it was 2WD, I wouldn't even ask, but with can I get away with replacing only two tires? It would be a shame to replace all four with so much lif left in them. Thanks.

[TheFNG]

If your overall outside tire circumference is within 1/16 of an inch, you are good to go. The problem is, this has to be the case for all four tires.

You can buy a tire from TireRack and have them shave the tread off to a specified amount, and this would be a cheaper option as opposed to buying four new tires (unless you need new ones anyway). Bear in mind that a patched tire will, in most cases, no longer meet its speed rating.


If I were you, this is what I would do. I think they only charge a small fee, and no doubt they will guide you on how to measure the tires properly so they can shave the proper amount.

Tires are pretty cheap in the grand scheme of things and not something *I* ever take chances with.

[blarg]

If your overall outside tire circumference is within 1/16 of an inch, you are good to go. The problem is, this has to be the case for all four tires.

of course, how often do you find yourself at 145 MPH? a patch will certainly throw off the balance, but as long as you rebalance the tire, you should be good up to 100.

[TheFNG]

of course, how often do you find yourself at 145 MPH? a patch will certainly throw off the balance, but as long as you rebalance the tire, you should be good up to 100.

Yeah, it isn't often that (most) people drive in the triple digits, but I personally won't risk it in a car that I know I will be punching every now and than.

A 1992 Accord, for ME, is a different case than a something built and designed for faster driving. Like I said, I consider tires pretty cheap in the grand scheme of things, and to me they are cheap insurance. Plus, this deal with having to replace either all four tires or having the tread shaved off of one (at a cost) is just the nature of the beast with AWD and I accept that.

[TonyG]

The tire shaving is a good idea. I tried adding a little more sealant to the tire. If it still leaks, I'll ditch it and get a new tire shaved. Thanks for the idea.

[ktmrider]

There was a debate about this back when I worked for Sears Auto about center diff damage. The VAG folks recommended tires matching within 1/16" ( or 2/32" ) or the Quattro fluid drive could overheat and not function properly. Not being very familiar yet with the Subaru system I cannot say for sure what could happen when a F/R or L/R delta occurs.
My 2 cents ( all it's worth ) is NEVER, EVER scrimp on brakes or tires! The only thing keeping your car in contact with the road are those rubber donuts ( at any speed ) and bringing the car to a stop are the brakes ( again at any speed ). I have no issue running patches ( preferred ) and/or plugs in a pinch but anything within 15mm of the sidewall is going in the death bin. That's what road hazard warranties are for. Plus mentioning the AWD aspect will usually get you multiple tires replaced at most reputable tire outlets.
OK, the soapbox is put away now. Peace!