How To Read Tire Sizes
MINT HILL, NC – Knowing how to read tire sizes is a really handy tool to have in your arsenal of car knowledge. Today, we’re going to break down a tire size to see just what each section means.
Let’s use P205/60R17 as our example size.
“P” indicates this is a passenger tire. these go on most cars and SUVs. You may also see “LT” which means “light truck” tire. These go on most mid and full-sized pickups.
“205” is the width of the tire in millimeters, so our example tire is 205mm wide.
“60” is the sidewall height. The wall of rubber between where your tire meets your wheel and the tread is called the sidewall. 60, in this instance, is a percentage. This tire’s sidewall height is 60% as tall as the tire is wide. We established earlier that our tire is 205mm wide, so this means our sidewall is 123mm tall.
“R” stands for radial. There are two ways of applying the layers of structural fabrics, called plies, to the insides of your tires – radial and bias. The “R” is simply indicating that your tire is a radial. Almost all tires since the late ’70s have been radial.
“17” stands for 17 inches or the diameter of your wheel. Ultimately, a tire’s bead – the rubber piece used to seal the tire to the wheel – has to be exactly correct in order to fit your wheel. A 17″ wheel must use a 17″ tire. This number simply indicates how big of a wheel you can fit inside.