Every 15,000 miles is usually the right time to change a tire. Some of the tires that we’ve listed above come with 20,000-mile averages, which means that you’ll be able to use your tires for a lot longer. A handy method of knowing whether your tires need changing is by inserting a quarter into the grooves of your tire. If you can see George Washington’s head from in between the grooves, then it means that your tire will be worn down sufficiently that it will need changing immediately.