A car's tires should be replaced when there is damage to the sidewall, when there are bulges sticking out and when there is a large gash or cut. Find out how to use a penny to check the tread wear on a tire with help from a certified master mechanic in this free video on car maintenance and auto repair.
Hello, my name is Mark Blocker. In this segment, we're going to cover, when should I replace my tires? Some of the indicators on when you should replace your tire, any time you see a bulge or a malfactioning point, thick things sticking out, some damage to the sidewall, a big gash or cut. If the tire is still holding air, that's going to be a safety issue, and that should be replaced, but to determine from where, when the tire is exceeding its wear limit, that varies from state to state, the local laws vary. In our area, it's about three thirty seconds of an inch, and a quick and easy way to determine that, is by using a penny, with the President Abe Lincoln side upside down. If you can insert the penny into the tread, and see the tip of Abe Lincoln's head, then that tire needs to be replaced. This one here, I can't see the end of his head, it still has adequate tread life. This one over here, I can clearly see the top of his head, thus indicating that the tread wear, is worn out on this tire, and should be replaced. A couple of other things to know, while you're doing that, look for uneven wear on the tire. If the tire is worn out, directly in the center of the tire, it could indicate an inflation problem, like you've got really too much air pressure. If it wears out on one side of the tire, or the other side of the tire, it could indicate that you have an inflation problem, but more likely, you've got suspension damage, and it needs some work, so those are some of the things to consider, when replacing your tires. If they wore out incorrectly before replacing it with new tires, it's going to have the same wear pattern on the new tires, so you'll want to get your suspension checked out. That's how you determine, when you should replace your tires.