Once you've put a certain number of miles on your vehicle, it's going to be time to buy new tires. Just like changing your vehicle's plugs and wires, tire industry nomenclature needs to be de-coded, so you select the best rubber for the road. As you will discover below, driving variables, such as road surface, weather conditions, speed limits and even your driving behaviors, will be accounted for as you decipher the hieroglyphics. Unless you're racing at the local drag strip or turning laps on an oval track, it is best to install the same brand, size, tread pattern and rubber compound on all four wheels of your vehicle. With that in mind, let's get started.
What does P215/60R16 mean?
Tire sizes most often begin with a letter. "P" indicates a passenger car tire. "LT" at the beginning or end of the tire numbers* would be for light duty trucks. "ST" is a special purpose tire and indicates strictly trailer tires. The first and second number on the tire will usually be separated by a forward slash and followed by the letter "R", which stands for radial-ply. Since all brands of passenger car tires have transitioned from bias-ply (or corded) to the safer and longer-lasting radial ply design, this should be the only letter you'll need to know.
For a P215/60R16 tire, the first number indicates the width of the tire's tread (215 millimeters) as measured from one side of the tire to the other. Both numbers are used to identify the tire's "aspect ratio", which is the width of the tread (i.e. - 215 mm or 8.46 inches) and the height of one of the tire's sidewalls expressed in a percentage of the width (e.g. - 60% = 129 mm or 5.07 inches). If you are trying to calculate the total height of a mounted tire, remember you have a top and bottom sidewall plus the diameter of the rim. The last number is the size of the rim. In this example, it would be 16 inches.
*NOTE: When LT (light truck) is used as the suffix, the tire is made for light to heavy-duty truck applications. A load identifier is used to distinguish tires designed for towing, carrying heavy loads or flotation (carrying loads or towing over loose such surfaces like dirt or gravel). Tires for commercial applications have a similar load designation but are identified with the letter "C".
It's a good time to change spark plugs too!
Selecting the right tires for your driving needs and keeping them properly inflated can save you money and benefit the environment with better fuel mileage. To ensure that you're not wasting money on unburned fuel exhausted into the air, take time to check your spark plugs, wires and ignition components whenever you buy tires. E3 Spark Plugs feature our patented DiamondFire technology that delivers a powerful flame front, which can bring new life to an aging engine. Our replacement truck and car spark plugs are the only plugs that are "Born to Burn".
