Once every month, or before you embark upon long road trips, check your tires for wear and damage problems. Bald tires tend to skid and slide on the pavement, and are more likely to be damaged by potholes and other road hazards. The tread on your tire should be at least 1.6 mm deep. If it isn't, the tire must be replaced.
To help you see tread problems, tires have built-in "tread wear indicators." These are narrow bars of smooth rubber that run across the tread: When the tread is even with the bars, it is worn down to the minimum level and must be replaced immediately.
You can also perform a simple test using a penny.
For more serious problems, we've created an easy-to-use online tool below to help you identify issues and learn how to fix them. (And if you need new tires, there's an easy-to-use Tire Selector tool.)