The most important piece of real estate on your car is those four small contact points that grip the road – the one you know as your tires. Those few square inches of rubber determine just about everything. Tires harness the engine’s power, allow the brakes to do their job, and determine how successfully a car will go around a corner. Tires are made up of a complex assembly of cables and rubbers, molded into a highly engineered profile. They are then mounted onto a wheel and inflated with air to give it shape and definition.

When it is time to go shopping for those all important tires, brush up on your knowledge about the tires your vehicle needs. According to Edmunds the sidewall of your tire is filled with important information that tells you everything you need to know. For example, the number P215/65R15 means the following: P means passenger tire, 215 means nominal width of tire in millimeters, 65 means the ratio of height to width, R means Radial, 15 means Rim diameter code. This is the number that most of us would use when we go shopping for tires, it is necessary to know what all of it means. There are also numbers indicating the load index and speed, severe snow conditions, the U.S. DOT tire ID number, max permissible inflation pressure, max load rating, tread wear and traction, tire ply composition and materials used. All this information is on your tires for a reason, everyone needs to know what it means and how it affects them when tire shopping.

On every tire the tread depth is what determines whether your tire is worn out or not. U.S. coins can be substituted for a tire tread depth gauge as tires wear to the critical final few 32nds of an inch of their remaining tread depth. Place a penny into several tread grooves across the tire. If part of Lincoln’s head is always covered by the tread, you have more than 2/32” of tread depth remaining. According to most states’ laws, tires are legally worn out when they have worn down to 2/32” of remaining tread depth. To help warn drivers that their tires have reached that point, tires sold in the US are required to have indicators molded into their tread design called “wear bars” which run across their tread pattern from their outside shoulder to inside shoulder. These wear bars are a necessary piece of information that will help keep everyone safe.

New tires do come with warranties. Each manufacturer specifies the duration of their tires’ limited warranty in months or years from the date of purchase. All tire warranties begin at the time of delivery for new vehicles and at the time of purchase for replacement tires. Tire warranties also expire when the tire’s original tread is worn down to 2/32” (1.6mm) of the remaining tread at which time the tread blocks are worn flush with the tread wear indicator bars. Warranties on replacement tires only apply to the original owner and vehicle upon which the set of tires was initially installed.

All warranties vary from one manufacturer to another, most have fine print regarding workmanship and materials, road hazard coverage, and uniformity. All of this fine print can be very confusing and difficult to understand. When it becomes too much to understand, contact the helpful folks at Good Works Auto Repair in Tempe or Mesa, they can help you will all your questions. It may come as a surprise to you, but Good Works sells all the major brands of tires and are well-equipped to install, repair, inspect, and maintain your tires. Each of us climbs in our car everyday trusting it to get us to our destination and back again. Well maintained tires will get us there and back. Knowing what we are shopping for will make it easier and will help us to know when we make the right decision.