# Significantly Uneven Tread Wear: A Theory/Question **URL:** \ **Category:** In My Humble Opinion\ **Created:** [October 3, 2016, 6:18pm UTC](https://boards.straightdope.com/t/significantly-uneven-tread-wear-a-theory-question/767578 "2016-10-03T18:18:49Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![Kimballkid](https://avatars.discourse-cdn.com/v4/letter/k/b5a626/32.png) [@Kimballkid](https://boards.straightdope.com/u/Kimballkid)\ **Post date:** [October 5, 2016, 7:22pm UTC](https://boards.straightdope.com/t/significantly-uneven-tread-wear-a-theory-question/767578/21 "2016-10-05T19:22:00Z")
> [@Kimballkid](#): > > Are you sure there is nothing wrong with the suspension on that side that might cause the problem? > [@Misnomer](#): > > How would I know? Is that something the shop that just did the 12-month/45,000-mile service would have noticed? (Or that any shop I’ve been to in the past three years would have noticed?) The shop I take my car to does an all-over inspection every second or third time I take it in. If they find something funny, they let me know. That’s how they found I had a broken rear leaf spring as well as a bad tie rod end, bad wheel bearing and needed shocks and struts. ---
**Author:** ![Jeff\_Lichtman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jeff_lichtman/32/1531_2.png) [@Jeff\_Lichtman](https://boards.straightdope.com/u/Jeff_Lichtman)\ **Post date:** [October 5, 2016, 7:29pm UTC](https://boards.straightdope.com/t/significantly-uneven-tread-wear-a-theory-question/767578/22 "2016-10-05T19:29:55Z")
> [@Chefguy](#): > > What kind of car? I know that Subaru tells you that if you change one tire, you have to change them all for some reason. Or at least that’s what my neighbor told me and he’s a fanatical researcher when it comes to buying cars. That’s because almost all Subarus have all-wheel drive. If the tires aren’t all the same size, it can cause excessive wear to parts of the drivetrain. It can also cause the AWD control system to route power away from the smaller tire, and to cause the car to be in the wrong gear. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [October 5, 2016, 9:57pm UTC](https://boards.straightdope.com/t/significantly-uneven-tread-wear-a-theory-question/767578/23 "2016-10-05T21:57:50Z")
> [@Jeff\_Lichtman](#): > > That’s because almost all Subarus have all-wheel drive. If the tires aren’t all the same size, it can cause excessive wear to parts of the drivetrain. It can also cause the AWD control system to route power away from the smaller tire, and to cause the car to be in the wrong gear. I’ve had several AWD cars and don’t recall any warnings about that. Better check my current CX-5 owner’s manual I guess. ---
**Author:** ![california\_jobcase](https://avatars.discourse-cdn.com/v4/letter/c/9d8465/32.png) [@california\_jobcase](https://boards.straightdope.com/u/california_jobcase)\ **Post date:** [October 6, 2016, 12:36am UTC](https://boards.straightdope.com/t/significantly-uneven-tread-wear-a-theory-question/767578/24 "2016-10-06T00:36:50Z")
> [@Misnomer](#): > > Nope! I hadn’t even heard of a treadwear number/rating until your post. 🙂 Apparently these things are very model-specific (i.e., just looking up “Goodyear Eagle” isn’t specific enough), so I’ll have to check out that data the next time I remember to look up my specific tires. > > Thanks! It’s stamped on the sidewall of the tires. A higher number is supposed to mean a more durable tread, but I’ve heard that manufacturers assign their own numbers, so they may not compare strictly between brands. ---
**Author:** ![Misnomer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/misnomer/32/14897_2.png) [@Misnomer](https://boards.straightdope.com/u/Misnomer)\ **Post date:** [October 6, 2016, 3:43pm UTC](https://boards.straightdope.com/t/significantly-uneven-tread-wear-a-theory-question/767578/25 "2016-10-06T15:43:40Z")
> [@Chefguy](#): > > What kind of car? Nissan 370Z (RWD). > [@Kimballkid](#): > > The shop I take my car to does an all-over inspection every second or third time I take it in. If they find something funny, they let me know. That’s how they found I had a broken rear leaf spring as well as a bad tie rod end, bad wheel bearing and needed shocks and struts. Ok, so if there were a problem with my suspension my shop would have noticed it. So that’s not the issue. > [@california\_jobcase](#): > > It’s stamped on the sidewall of the tires. A higher number is supposed to mean a more durable tread, but I’ve heard that manufacturers assign their own numbers, so they may not compare strictly between brands. Thanks again! ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [October 7, 2016, 4:52pm UTC](https://boards.straightdope.com/t/significantly-uneven-tread-wear-a-theory-question/767578/26 "2016-10-07T16:52:00Z")
I’ve only seen the term “rotate” referred to once in the whole thread. Are you not rotating your tires? ---
**Author:** ![Misnomer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/misnomer/32/14897_2.png) [@Misnomer](https://boards.straightdope.com/u/Misnomer)\ **Post date:** [October 7, 2016, 5:02pm UTC](https://boards.straightdope.com/t/significantly-uneven-tread-wear-a-theory-question/767578/27 "2016-10-07T17:02:39Z")
Of course I rotate my tires. I check the tire pressure regularly, too, which hasn’t been mentioned at \*all \*in this thread. Surprised you didn’t ask about that. 😉 ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [October 7, 2016, 5:11pm UTC](https://boards.straightdope.com/t/significantly-uneven-tread-wear-a-theory-question/767578/28 "2016-10-07T17:11:44Z")
Except for post #2. ---
**Author:** ![Misnomer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/misnomer/32/14897_2.png) [@Misnomer](https://boards.straightdope.com/u/Misnomer)\ **Post date:** [October 7, 2016, 5:23pm UTC](https://boards.straightdope.com/t/significantly-uneven-tread-wear-a-theory-question/767578/29 "2016-10-07T17:23:19Z")
Crap. 😃 [Previous page](https://boards.straightdope.com/t/significantly-uneven-tread-wear-a-theory-question/767578.md?page=1)