What Is a Tire Q Rating?

by Charles Green

Every tire is speed rated, which means that you can safely travel at a certain speed limit without worry that your tires will fail you. Tires are assigned a letter rating representing the top speed you can drive.

Function

Review the ratings. Nine separate letter ratings are assigned to passenger vehicle tires with Q the lowest and Y or Z the highest. Each letter stands for the top speed you can drive under ideal road conditions.

Q Rating

Understand the Q rating. Q is the lowest rating, but with a maximum speed of 99 mph, you should safely be able to put these tires on your car. Certain western states have a posted speed limit of 75 mph, thus you are well within the range of these tires.

Rating Locator

Find the speed rating. On the sidewall of your tires, you can find a series of numbers and letters. Immediately following your tire's size, which will look something like P215/65R15, you'll see an alphanumeric combination such as 89H. The numbers represent vehicle load factor, and the letter is the speed rating.

About the Author

Charles Green is a freelance writer in North Carolina who has been writing since 1992 and freelancing since 2002. His work appears in "435 South Magazine," "Wisconsin Golfer" and for various websites. Green earned a Bacheler of Science in business administration from Ramapo College of New Jersey.

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