Your tires should be smooth and round. If you notice a bubble on the sidewall, or see a section of tread bulging, it’s a sign that something is very wrong. Is it safe to drive with a bubble in your tire? The answer is a firm NO.

A few important things to watch out for include:

  • Bubble in the sidewall: The most common place to see a bubble in the tire is the sidewall. This is often caused by driving for even a short distance with a flat tire. What happens is that when the tire goes completely flat, part of the sidewall will slip under the edge of the wheel. This creates significant wear.

It can also occur after bumping a curb, or driving through a pothole. The force of hitting a hard edge in the road can pinch the tire against the rim, which causes a bubble to form.

A bubble can be produced in areas where the rubber has worn very thin. If you attempt to drive on the tire, there is a high possibility that it will blow out on you. Generally, there are no symptoms of a bubble in the sidewall that you’ll feel – you’ll see the bubble when you check your tires, though.

  • Bulging tread: If you see a bulge in the tread, rather than a bubble in the sidewall, this indicates that the tire has a broken belt (the steel belts that run around the circumference of the tire on the outside, underneath the tread). You’ll also experience a rhythmic “bumping” while driving.

Often, the bumping sensation is the first sign that something’s wrong. If you notice a bulge in the tread, you may be able to drive for a short distance, at least so you can get somewhere safe to install the spare. Do not drive for long distances with a bulging tire, as the tire can fail completely at any time. Your top priority should be getting the tire replaced as soon as possible.

If you experience any of these problems, you need to have the tire replaced immediately. It’s recommended that you replace tires two or four at a time, and stay on top of rotating your tires on schedule.