With the number of AWD cars on the road, you'd think that tire shaving and truing would be more popular. But I had to call the manufacturer of the truing machine and obtain a buyer's list to find anyone in my area that does it. Even still, there's only 5 people on that list in all of NYS. The guy closest to me, only one on the island, said he'll do it, but he mainly deals commercial and he sees no need for me to do it.

I recently had a blowout on one of New York's infamous potholes and I JUST REPLACED all my tires (due to another pothole earlier in the year) a year ago. Needless to say I don't want to do that again... money aside, it kills me to be throwing away perfectly good tires given the environmental impact of tires.

I saw Tire Rack offers tire shaving so that you can match the wear with the other tires, but you need to also buy your tires from them.

So why is this not more common? Are there laws in place against it (like tire retreading )? I mean the only thing I can think of is it's probably not very profitable, given that tire shops are in the business of selling tires, they'd rather you buy 4 new ones. But that's all I've got.

  • Perhaps it depends on the characteristics of the particular AWD system... Some are, or have been, known to have an issue with differing diameters, others are more tolerant.
    – Solar Mike
    Jan 15 '19 at 14:38
  • This might not be that helpful, but I find that punctures and blowout events just aren't that common, personally speaking. I imagine it would depend on the roads in your area. That begs the question, why aren't there more shops that offer this service in New York in particular, but I suppose in general, there aren't that many, because in general, it doesn't happen very often. Jan 15 '19 at 14:43
  • I have a feeling you are looking in the wrong places for this type of service. Shaving tires happens all the time in road racing and track days type of performance applications. More rubber between the core of the tire (where the belts reside) and the road has more flex, which does not help with adhesion. Shaving the tires helps with side loading g-forces, which means a car can go around a corner better. If there are any road racing tracks around, they will have or know where you can find a business which can provide this service for you. Jan 15 '19 at 16:31

Perhaps it depends on the characteristics of the particular AWD system... Some are, or have been, known to have an issue with differing diameters, others are more tolerant.

If the numbers are too small, then shops will not invest in very expensive equipment that only gets used a few times per year, as it will not pay for itself. Obviously they cannot charge too much for that shaving service..


The reason few people do this is not only is this not needed, it's not recommended.
If you want thinner tires, simply buy lower mileage rated tires. They have lower tread. Why would you buy a $140 tire and then grind half of the life off of it?

an AWD system does not care a single bit about a .05% difference in tire sizes. These machines are a scam. Your differentials make up the difference.

Additionally, the thinner you make your tire, the more likely you are to suffer from flat tires. The thickness of the treads protect against road debris.

I'm not sure what your pothole reference is even related to, as that was caused by you nailing a pothole, not the tread thickness.

  • Why then does the whole internet tell you to replace all your tires on an AWD vehicle? I mean my tires are kind of middle of the road. $80 Hankooks, but it's still wasteful to buy 4 new tires in my opinion. Jan 15 '19 at 16:33
  • Some awd vehicles have a fluid based vicsous cuoplling that can overheat if there is sufficient difference in rooling radii of the tires , iirc correctly some volvos and others - a very expensive repair making a set of 4 tires cheap in comparison...
    – Solar Mike
    Jan 15 '19 at 16:42
  • 1
    @JohnLord - In this case it isn't the differential which you'll cause issues with, but rather the transfer case (can also be considered a center differential or viscous coupling). Subaru is one of the BIG manufacturers who state you should not have a single tire which is different from the others. Read this and this if you have questions. Jan 15 '19 at 16:44
  • if a small variation was a huge deal, you would not be able to ever mount that ridiculous donut spare. I doubt there has ever been a single instance of failure unless the vehicle is posi-track or has a chain differential and new vehicles don't. In fact i'll go one more level: You'll see a larger equivalent variation in tire size just from sitting in the car. They are air-filled and compress.
    – John Lord
    Jan 15 '19 at 20:40
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    Looks like i'll have to take a hit on this one. I talked to a shop and they told me that there in fact is one car with an awd system that not only can't tolerate different tire sizes mere millimeters different in size, but it even has a problem with tread types. The story goes that it will cause the car to eat up the gears eventually. I don't remember the exact car but I do remember it was an import that has full-time awd. If the manufacturer is claiming this, I can't argue with it, but if this is actually the case, they shouldn't have ever sold that awd system in the first place.
    – John Lord
    Jan 21 '19 at 2:43

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