Tire Question. Car Tires. For a Car.

[SacramentoMike]

With all the expertise around here, figgered this was a good place to ask.  My wife took her Subaru Forester in for a random scheduled service yesterday and they told her she has a nail or something in one of the tires.  There has to be at least 20,000 miles left on that set of tires, but they're recommending she replace all four tires!  :weirdsmiley:   Tread depth is at 7/32" now, and most state government inspections fail tires at 2/32nd.  The dealer recommends replacing at 5/32".

Is it possible they just like to sell tires in sets of four?   An internet search raises some questions, like having one newer tire could have some harmful effect on the all-wheel drive function (somehow.  Don't know how, but I don't know anything about this, period.)  The tire with the nail has a very slow leak right now, would last a week or more before needing a couple or three pounds of air, but they (whoever "they" are) say it could cause a sudden failure.  Not good.  I don't mind buying the one, but replacing 3 good tires??  So the wife talked to the dealership, and they said they could somehow shave a new tire to bring it equal to the other 3.  Odd thought.

But as I said, I don't know, and mainly, it's her car and she's going to want to be comfortable.  I'd buy one and drive on, myself, but she's not quite ready to do that.  What do you tire experts think? 

 

[Bugnatr]

First off, have the tire removed and patched by a tire shop, if they can. Problem solved.

I had a tire on my awd Highlander that had a staple in the shoulder and couldn't be repaired but the tires were a bit less than half worn. I talked to a local mechanic (you know the one who rides a S10) and he said it's okay to replace just one tire but not two, I believe I read the same thing on the net. He felt the differential will compensate for the difference in the tire wear.

Think about all the folks who don't rotate their tires and yet the vehicles keep going.  Her tires may be well past half way then I probably replace all four instead of just one tire.

I had a customer who put the wrong size tires on their Chrysler and it ruined the trans or transfer case (I forget which). 

Just my .02 and I didn't stay at a Holiday Inn last night. YRMV

 

[infrared]

Mike,

There are tire patches, tire plugs, and combo patches.  The combo is a large flat patch, with a center stem that comes from the center of the patch.  The patch goes inside, of course, and the center stem gets pulled outward through the puncture hole, like a tire plug would.  When the tire is patched and fully inflated, then the center stem is trimmed off carefully with a sharp blade, even with the tire surface.  Do not leave any of the stem extended outward of the tire's road surface; cut it exactly flush, not recessed.

That should do the job.  A good inside patch would be almost as good, usually.

It's best if tire diameters are identical on FWD/AWD vehicles, sure.  The tire shop was not wrong, but not completely forthcoming, either.

PM inbound, not related to this issue.

 

[escapefjrtist]

Echoing 'Bug, take the car to a tire shop and have them repair with a plug / patch. Done. With 7/32" thread depth remaining it's ridiculous to replace the tires. Depending on the brand, the tires only had 10/32" - 11/32" to start with.

~G

 

[harper]

Tire shops can only legally repair a puncture in the tread. It is illegal for them to attempt to repair a puncture on the sidewall. Sidewalls flex like crazy and a plug or patch there can fail badly. Take it to Les Schwab or Discount Tires. They'll tell you if they can patch or plug it. If you are a regular customer (and usually even if you're not), they'll do it for free. I've string patched lots of car tires on my own and there's nothing to it, as long as it's in the tread.

 

[Ignacio]

The theory is from the point that dealers won't patch a tire anymore as a policy and/or business decision they can get away with on people that are patch paranoid.  And from that logic point then there is potentially a wear issue on the spider gears in the drive train.  There's limited slip between the two sides, but the 4WD system prefers each side to have the same diameter tires. W\ill your car blow up?  No.  Can something in the driveline wear out prematurely?  Possibly.

Agree to take it to a non-dealer and have it patched.

 

[SacramentoMike]

Great feedback from everybody!  Thanks.  So it's her car and her decision but I wanted to give her some input from somebody with no dog in the fight--and more expertise than I have, this being one of those (very few, really) subjects I don't know jack about.    But she made an appointment for tomorrow a.m. and this is plenty for her to take in.  I think she's open to the idea of the patch if the shop (America's Tire--we've used them before and always been satisfied) will do it and the problem is in an okay spot, etc.  Hey, at least we won't be buying a set of four!