[Hump66]

Forgive my ignorance but I've never had a car with a warranty before. Are tires covered under the B2B warranty? What would cause this and would it be covered? Seems the tread is chipping/chunking out along the outside edges.

 

[Hump66]

Technically, they are not. But depending on how many miles you have on the car, and who your dealer is, they may help you out. Are all 4 doing this, or just 1?

Almost 29 miles, 3 of the 4 are but blew one today on road debris.

The factory tires are covered under a separate warranty that should have been provided when you purchased the car. What you're seeing on that tread can be caused by any number of things - improper balancing (doesn't take much), lots of very hard cornering (not likely but I've seen tires do this when inflated past the sidewall PSI and cornered hard), and really rough roads on seriously under inflated tires. The fact that the chips are on both sides makes me think balance is the most likely culprit. Based on the apparent tread depth those tires look like they're about two thirds of the way through their life span.

Now for the good news, other than making the tires really noisy you're not looking at an immediate safety hazard. Just keep an eye on them to ensure the chipping doesn't get down past the tread depth.

Inflation is good, 34psi, but OK roads are horrible in general. I'll check into the separate warranty you mentioned.

Looks like gravel road damage.

20 years ago I had a very expensive set of Goodyear Eagles go like this after the rubber had aged about five years and I drove about three miles on a gravel road.

I have strenuously avoided gravel roads ever since.

I've never taken it down a gravel road, mostly all highway and some city streets. I can't speak for the previous owner, and I only noticed it since I had the flat today.

 

[Hump66]

It may be in your best interest to just bite the bullet and put a new set of quality tires on the car. The fact that you had a flat on one tire and the tread on three of them is damaged like this makes me wonder just what type of roads the previous owner was driving on. Which trim do you have?

I have a 2015 LTZ RS.

 

[Hump66]

To me those tires look like they have experienced some off road abuse, including spinning/sliding a lot...

Someone had more fun in it than I've had a chance to so far.

No, I'm not talking about road hazard coverage, I'm talking about an out-of-round condition or other problem covered under the tire warranty due to a tire defect.

If anyone can tell me the brand of the OP's tire, I can link to the warranty info from that company. OE tire warranties are complicated because the tire is also warrantied by the tire company. See below for more info.

It's a moot point in this discussion, though, because that's not what we are taking about with the OP's tire.

Anyway, here's the language on GM's warranty page for 2016 models:

They are Michelin Pilot MXM4, 225/45-18