There are two popular ways to check for signs of tire tread wear. One easy way is the penny test. Simply insert a penny into your tire's tread groove with Lincoln's head upside down and facing you. If you can see all of Lincoln's head, it's time to replace your tires.

Another way is to look at the tread wear indicator bar that's molded into your tires. The bars are located at the bottoms of the tread grooves in several locations around the tire. When a tire is so worn that these bars become visibly flush with the adjacent tread ribs, it's time to replace the tire.

Goodyear suggests you check your tire tread using either method every 3,000 miles.

Know What Certain Wear Patterns Mean

As tires wear, sometimes wear patterns emerge that can indicate problems with your vehicle or tires. If you see any of these patterns, have your tires checked by a professional Goodyear Retailer. Here are some wear patterns to watch for.

Wear on both edges: UNDERINFLATION

Underinflation of a tire reduces its tread life by increasing the tread wear on its outside edges, or shoulders. It also generates excessive heat which reduces tire toughness. Finally, it reduces fuel economy through increased rolling resistance because soft tires make your vehicle work harder. Abnormal tire wear may also be caused by misalignment or mechanical problems.

Wear in the center: OVERINFLATION

When a tire is overinflated, the center of the tread bears most of the load and wears out faster than the outside edges. Uneven wear reduces the useful life of a tire. It could also be the result of misalignment or mechanical problems.

Cups or dips in the tread: WORN PARTS

Cupping (also called dipping) is most common on front tires, although rear tires can cup as well. It may be a sign that wheels are out of balance or that suspension or steering system parts are worn out.

Sawtooth edges: MISALIGNMENT

If the edges of your tire tread take on a sawtooth or feathered appearance, it's because of erratic scrubbing against the road. The solution is an alignment correction.