Advice from a AAA Car Care Center Manager.

AAA World Article

How do I know what my tire size is?


The first and best place to look is your driver’s-side doorjamb, where you should find a sticker that shows not only your front and rear tire sizes but also the air pressure ratings that are best for both. The second and usually most obvious place to look is on the tires themselves; however, not knowing what a tire size looks like could cause you to read the wrong numbers or not find them at all. Sometimes the tires on the vehicle aren’t correct, so I always recommend looking at the sticker.


How do I know if I need to replace my tires?


Replacing your tires can be an expensive proposition and one that is sometimes unexpected. Here are a few ways to check the condition of your tires.


The Penny Test—Insert a penny into the groove of your tire with Lincoln’s head upside down and facing you. If you can see all of Lincoln’s head, it’s time to replace those tires. 

Tread depth gauge—Go to a local auto store to purchase a tread depth gauge, the most accurate way to measure your tire tread depth. The gauge makes it easy with color coding: green being good, yellow meaning you’re getting close, and red indicating you need new tires.

Tread wear barsAlmost every tire has tread wear bars. The bars are located at the bottom of the tread grooves in several locations around the tire. When these bars become flush with the tread, it’s time to replace your tire.


What basic maintenance should be performed on tires?


Tires should be rotated every 5,000 – 6,000 miles. Rotating the tires is important because a cars front tires wear out faster than the rear tires. This is true for all-wheel drive and two-wheel drive. Regular rotation will help all four tires wear more evenly.


Wheels should be aligned every 12,000 – 15,000 miles. Wheel alignment affects tire wear but also fuel economy, tire performance and vehicle handling. Wheel alignment is also a big factor in a vehicle’s steering response. Getting regular wheel alignments prevents shoulder wear and feathering. Both symptoms are cause for premature replacement.