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Discussion Starter · #1 ·
So does anyone have any experience with getting a tire shaved? I got new tires last summer and they are only 3/32 worn down and the thought of having to replace 3 tires with 8/32 on them I plan on getting one shaved to that level. I should get 2 more years out of these I would imagine since I dont put a lot of miles on it. Has anyone gone this route? $100 for tire and shaving vs $800 for replacement of all 4.

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I interesting. ??So you have found a place that will shave tires.???

I had no idea that was a thing. I have always dreaded the first 30k miles of tire life for that exact reason.

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I understand the importance of having all 4 tires the same diameter on an AWD vehicle lest the AWD system 'sees' the difference in wheel/tire RPM when vehicle is rolling. This can destroy the AWD components.

You did not mention the mileage on your existing tires,

I had to replace a tire at about 6,000 miles. They told me the difference in diameter was not significant enough to warrant shaving.
 

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2020 Outback Premier 2.5i
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I've seen posts and tire sales outlet data that says 2/32 variation is OK and to put the odd size tire on the rear so that both fronts are the same. Not sure I'd believe any tire outlet that advised me to not worry about being 1/32 over tolerance. Probably means they don't have the ability to adjust a tire radius. Now if you could only do a burn-out with an OB. ;)
 

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So does anyone have any experience with getting a tire shaved? I got new tires last summer and they are only 3/32 worn down and the thought of having to replace 3 tires with 8/32 on them I plan on getting one shaved to that level. I should get 2 more years out of these I would imagine since I dont put a lot of miles on it. Has anyone gone this route? $100 for tire and shaving vs $800 for replacement of all 4.

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My dealer offers that service for about that price and highly recommends it as the traction control computer, I was told, cost 8k to replace!
 

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2018 3.6 Touring (Canadian, so Premium I guess?)
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Check on road hazard warranty; the retailer or manufacturer may eat the cost of the replacement. I’ve had two replaced on different vehicles under road hazard, both purchased at Costco.
 

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Might help knowing where you are... someone here might be able to help,

tirerack tires bought from tirerack can get shaved, they also do it in their distribution centers if you are near one of them (like 6), the occasional rare shop does it. Anyone do racing tires near you?

Discount tire says no way no how and anyway it voids the warranty

Around here, the only one I found near me is this guy in NY, but racing-centric work in general (makes me wonder if looking for a racer's shop might not be a bad idea if they do that for their slicks).


Has to be more than that, they just aren't putting on their web sites... otherwise the tire shaving machin guys would be out of business.
 
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Aahh, but for the good old days when I ran 14" on one side and 15" on the other.
OK, I'm kidding!!
Just saying that if you were in the auto tech world 40+ years ago as I was (licensed in 1979), it's amazing how complicated things have become. I still have my analog multi meter for setting dwell. Now if I could only have my dream car - 1967 S-code Mustang 390, then I could still use it.
 

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Discussion Starter · #11 ·
I bought the tires ar Evan's Tires in San Diego, I have road hazzard but they said they will replace the one for $50 but the others are not covered. Did Costco replace all 4 under the road hazzard warranty? I have 40,000 miles on the car, not sure how many miles on the tires, but not significant wear. Was going to try to sell them, the three 8/32 tires and one new one for ~$200 but no bites and dont want to store them until they sell. I figure I can get another 2 years on these, my daily commute is only ~ 12 miles. I found a local shop that will send them to their shop in Bellflower to shave them. They say it's not common on road tires, mostly offroad, and he said it seems a waste to shave a new tire but I told him it's that or ~$800. Evans wont mount the tire since it is greater than 2/32 but will sell it to me with the understanding if i put it on it may cause damage and I also void the warranty on the new tire.

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Discussion Starter · #12 ·
Aahh, but for the good old days when I ran 14" on one side and 15" on the other.
OK, I'm kidding!!
Just saying that if you were in the auto tech world 40+ years ago as I was (licensed in 1979), it's amazing how complicated things have become. I still have my analog multi meter for setting dwell. Now if I could only have my dream car - 1967 S-code Mustang 390, then I could still use it.
I had my truck stolen years ago, I had an analog Simpson multimeter, that was one of the things I couldn't replace.

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Discussion Starter · #13 ·
I understand the improtance of having all 4 tires the same diameter on an AWD vehicle lest the AWD system 'thinks' there is a tire spinning. This can destroy the AWD components.

You did not mention the mileage on your existing tires,

I had to replace a tire at about 6,000 miles. They told me the difference in diameter was not significant enough to warrant shaving.
They told me it was 3/32+ difference

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Discussion Starter · #14 ·
Might help knowing where you are... someone here might be able to help,

tirerack tires bought from tirerack can get shaved, they also do it in their distribution centers if you are near one of them (like 6), the occasional rare shop does it. Anyone do racing tires near you?

Discount tire says no way no how and anyway it voids the warranty

Around here, the only one I found near me is this guy in NY, but racing-centric work in general (makes me wonder if looking for a racer's shop might not be a bad idea if they do that for their slicks).


Has to be more than that, they just aren't putting on their web sites... otherwise the tire shaving machin guys would be out of business.
I'm in San Diego, they said they do it more for offroad racing.

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Discussion Starter · #15 ·
Check on road hazard warranty; the retailer or manufacturer may eat the cost of the replacement. I’ve had two replaced on different vehicles under road hazard, both purchased at Costco.
Did Costco replce all 4?

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Discussion Starter · #16 ·
I've purchased shaved tires from The Tirerack with success. Do they sell the tire you need?
I can get the replacement discounted but good to know if anything happens to this one I can go through TireRack. Thanks for the info.

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2018 3.6 Touring (Canadian, so Premium I guess?)
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Did Costco replce all 4?

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No, in both cases the tires were almost new so they just replaced the damaged one, no shaving required to get within spec of the other tires. Also, neither was full time AWD, so not nearly as picky about one being less than 1/32 different (FWD Honda Odyssey and an F150 part time 4x4)
 

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3/32 difference should be OK, as the circumference difference is still under 1/4". A good article from Dunn Tire addressing this very issue:

.
 

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3/32 difference should be OK, as the circumference difference is still under 1/4". A good article from Dunn Tire addressing this very issue:

.
IF the often-cited guidance "All of the tires on your AWD Subaru must be within 1/4 of an inch of rolling circumference" is really true and what Subaru still contends-- I don't agree with the math in the linked article that concludes 3/32 difference in tread depth is acceptable.

Math facts:
Circumference = pi X Diameter.
pi = 3.1416

It the tread depth is reduced by 3/32 or .09375 inch, the diameter of the tire is reduced by twice that, namely .1875 inch
The circumference would therefore be reduced by .589 inch in that case which is more than twice the alleged allowable difference in rolling circumference.

To maintain a circumference difference of .25 inch or less, tread depth must be different by no more than (1-1/4) /32. That's the kind of treadwear that easily can easily result in new matched sets of tires after a standard rotation interval! Or, for that matter, equivalent to a circumference difference that I would surmise could exist even due to the different weight loads front to back.
 

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IF the often-cited guidance "All of the tires on your AWD Subaru must be within 1/4 of an inch of rolling circumference" is really true and what Subaru still contends-- I don't agree with the math in the linked article that concludes 3/32 difference in tread depth is acceptable.

Math facts:
Circumference = pi X Diameter.
pi = 3.1416

It the tread depth is reduced by 3/32 or .09375 inch, the diameter of the tire is reduced by twice that, namely .1875 inch
The circumference would therefore be reduced by .589 inch in that case which is more than twice the alleged allowable difference in rolling circumference.

To maintain a circumference difference of .25 inch or less, tread depth must be different by no more than (1-1/4) /32. That's the kind of treadwear that easily can easily result in new matched sets of tires after a standard rotation interval! Or, for that matter, equivalent to a circumference difference that I would surmise could exist even due to the different weight loads front to back.
I should have specified "rolling circumference" - the compression of the tire from vehicle weight is a factor in this, which reduces both diameter and, by mathematical calculation, is different than the actual circumference of the tire assuming fully inflated. This is where the MAXIMUM 3/32" of an inch comes from, as the diameter of the tire while rolling is NOT the same as the diameter of the tire when sitting weightless and full to the max with air pressure.

I appreciate the math, which is applicable in a perfect world, but the rolling of a tire is not perfect. Look at your tires when your vehicle is parked and they are slightly compressed. That of course will be reduced considerably when moving, as the dead weight is replaced by moving mass, but it is still there.

Dunn Tire published that article. While not Tire Rack or Discount Tires in size, they are a pretty large chain in WNY and Northern PA and I doubt they would put info online that would compromise customer safety.

Rolling circumference can be calculated, but the simple answer is to place a marking dot on the tire, and measure the straight line distance from the first time the dot hits the pavement to the second.

In short, the MAXIMUM 3/32" is a good calculation when all environmental factors are taken into account. But if all 4 makes you feel better, then do that. Shaving a tire is a skill so make sure whoever does it knows what they are doing (ideally has race experience where this type of work is more common)
 
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