When to Replace Your Tires
Worn tires have very negative effects on your vehicle. They also create incredibly dangerous driving conditions. A worn tire has poor traction, especially in bad weather, and can be blown out or go flat at any time.

To prevent possible catastrophe, use the "Honest Abe" test. In this test, you will take a penny and stick it in the tread of your tire with Abe Lincoln upside down. If you can see his whole head, you need new tires.