What do the Numbers on My Tires Mean?
Many people don’t notice or care what is written on the tires of their car. They really only care that they don’t pop or deflate and allow them to go to their destination safely. While most people do get their tires checked every so often, like during regular oil changes or when they change their tires between seasons, some people will forgo checking their tires until it’s too late. Don’t make that mistake, learn what is written on your tires and what those numbers mean!
Standard Passenger Tires
The most common tire you will encounter through your driving life is a passenger tire, unless you are a professional truck driver or drive a motorcycle most of the time. A standard passenger tire will have something written on it like “P215/65 R15” on the sidewall. This sequence of numbers and letters tell you five different things: the type of tire it is (P = Passenger), tire width, aspect ratio, tire construction, and tire diameter or size.
The width of the tire is determined by the first number in millimetres. In our example, the width is “215” which means that the distance between each end of the sidewall is 215 millimetres.
The aspect ratio is a percentage that tells you the ratio of the tire’s height to its width. In our example above, the aspect ratio is 65, which tells us that the tire’s height is 65% of its width.
The construction of the tire is determined by the capital letter that is next in the sequence. You will most likely encounter a capital “R,” which tells you that the layers are radially run across the tire. You may also see a “D,” which means that the tire was constructed on a diagonal or bias ply.
Tire Diameter or Size
The last number in the sequence determines the diameter of the tire. In our example, “15” is the diameter of the tire. This is an important number if you need to change your tires, as 15 is the size of your tire and will need to find another “15” tire to match the rest.
Other Tire Information
Your tires may also have more information written on it. This could include the maximum amount of inflation load limit when they are cold. This is important to know if you notice that your tires are losing air and need to refill them.
You might also find the treadwear, traction and temperature grades, the load index or speed symbol, and the tire ply composition plus the materials that were used to make the tire.
Get your Tires at 416 Wheels and Tires
Servicing Mississauga and the GTA, we have the best prices you will find on rims and tires. Located on the corner of Dixie and Queensway, we offer many different brands and wheel styles. Come in today to get your summer tires replaced before the first unexpected snowfall hits!