Speed Rating Load Index
There’s always more to learn at Pep Boys. Here’s the word on more of the words and symbols written on your tires.
Every tire is designed to withstand a specific level of speed over an extended period of time – think in terms of highway driving for example. The longer you drive at a certain speed, the more heat a tire will generate from the friction of that tire churning against the road surface and the side wall flexing.
A tire’s speed rating indicates the ability of that tire to handle a certain level of prolonged speed – and the heat it produces – without suffering deterioration in performance.
All tires in the in the U.S. are designed to maintain legal U.S. speed limits. A tire’s speed rating must match the maximum driving speed of the vehicle it’s mounted on. However, simply installing a tire rated for a designated speed does not mean the vehicle it’s mounted on can be driven safely at the tire’s highest performance level.
Below is a list of ratings coordinated with the speeds they represent. Note: These are not recommended speeds.
The load index is a numerical identifier assigned to each tire based on the ability of that tire’s size to withstand a certain load level of speed without deterioration in performance. The higher the load index value, the greater the load the tire can safely carry at the correct inflation.
Note: Pep Boys will only install tires that meet or exceed the original equipment manufacturers specifications for specific rating and load index.