In making a tire purchase, long tread life is among the most important features sought after by many consumers, yet our real-life treadwear tests have found so much variation between the promise and the reality that it’s impossible to use the stated tread-life to accurately comparison-shop between brands.

For that reason and others, Consumer Reports painstakingly performs vehicle treadwear testing and rates tires for tread-life. And now, we are introducing comparative mileage projections. (See the complete tire Ratings.) Of course, your actual mileage will vary by what, where, and how you drive among many other factors.

Many car tires come with a prorated mileage warranty, also called a tread-life warranty, that is often used as a selling point. Think of that mileage limit, generally somewhere between 30,000 and 100,000 miles, as a figure highly influenced by a marketing department. It may be close to what you get, but in the comparisons we’ve made, it may be way under.

Moreover, if the tire doesn’t live up to the wear promise, you may find that the so-called warranty imposes so many restrictions and conditions that it’s nearly impossible to collect on. It may even be pointless to try, although a diligent and truly determined consumer can sometimes manage it.

Read "The Truth About Tire Treadwear."

Car tires on rack

How It Works

A tread-life warranty is not a money-back guarantee. As with other prorated warranties, what you can collect is only a partial credit. With tires, that credit is usually good only toward the purchase of an` essentially identical tire from the same manufacturer. If you didn’t especially like those tires, and maybe wanted to upgrade to something better, tough luck. Then you get nothing.

The credit for premature wear is calculated as a percentage representing tire life you didn’t get. Let’s say you bought a set of 80,000-mile tires but they were worn out at 60,000 miles. That 20,000-mile shortfall would qualify you for a 25 percent credit off the standard retail price for the replacement. Your credit, though, is applied to the standard retail price, not any discounted price you may find. And tire discounts are very, very common. So, as a practical matter, your credit may be worth nothing.

The Fine Print

Before a retailer will even consider granting a mileage-warranty credit, you have to fulfill some pretty exacting requirements. These may vary, so read the fine print.

  • You have to have kept your original receipt, with your car’s odometer reading at the time of purchase, and whatever warranty papers came with the tires.
  • If there was a recommended tire-rotation interval, say every 5,000 miles, be ready to supply written documentation for each of those services.
  • The wear must also be absolutely even across the tread. If your tires ever got misaligned, or were under- or over-inflated so the wear isn’t quite uniform, there goes the warranty.
  • All this has to happen within a specified time frame, say four or five years.  

The Final Gotcha

You can only recoup something on a prematurely worn-out tire if the tire is truly worn out, with the tread’s wear bars level with the top of the tread. That indicates that you have only 2/32nds of an inch of tread, the legal minimum in most places. The danger is that a tire with that little tread will probably already have lost much of its hydroplaning resistance and snow traction.

We don’t think it’s very smart to drive around on barely-legal tires, especially to save just a few bucks. In fact, we recommend that you shop for tires when you still have 1/8 inch (4/32nds) of tread left. You can measure that with a quarter. Position a quarter in the tread grooves with George’s head pointing down. When you can just see the top of Mr. Washington’s head, that’s 1/8 inch.