Do I Need New Tires?
Check for the “wear bars” or “tread bars.” If you can see these little horizontal lines intersecting with the vertical lines of the tire at select points, then the tire is worn down.
Take the penny test: Grab a penny by pinching your fingers over the part that contains Lincoln’s body. Jam his head into the grooves. Your tire’s tread depth is ok if you can’t see the head.
Use a tread depth gauge to measure the precise depth (2/32 of an inch is the legal limit).
Regardless of specific tread conditions, tires should be replaced about every five years due to increased risk of failure. You don’t want to be forced to replace them (and potentially your entire vehicle) after skidding all over the highway during a storm.
Also, be sure to adjust the pressure regularly and rotate your tires to get the best fuel efficiency and longest life out of them.