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The Right Tire for Your Car
When choosing a tire for your car, it's important to select the correct size.
The first requirement is choosing one that can carry the weight of your vehicle: if the tire
is undersized, it will wear out quickly. Oversized, and the tire will show uneven tread wear.
Either way, the tire won't last and may even become a hazard.
How To Read the Sidewall
The side of your tire, known as the sidewall, contains all the information you need to know.
Regardless of the manufacturer, all tires are required to have the same information.
- Tire Type
This defines the proper use of the tire. On the tire shown, a P indicates a passenger car tire,
while an LT would indicate a light truck.
- Tire Width
The width of the tire, from sidewall to sidewall, measured in millimeters. On the tire shown,
the width is 215 millimeters.
- Aspect Ratio
This indicates the height of your tire. The higher the number; the taller the tire.
An all-season passenger tire will typically have an aspect ratio between 65 and 80.
The number represents a percentage of the height divided by the width (75%, 70%, 65%),
and is commonly referred to as the tire series (75, 70, 65).
For example: On the tire shown, the 65 represent the height, which is equal to 65%
of the tire's width.
- Construction
This indicates how the tire was manufactured. An R represents a radial construction, which
means that the body ply (layers of fabric that make up the body of the tire) runs perpendicular
to the tread. A B represents a bias construction, which means the body ply runs diagonally,
with the direction of ply layers alternating to reinforce one another.
- Wheel Diameter
This indicates the width of the wheel from one end to the other. On the tire shown, the diameter
of the wheel is 15 inches.
- Load Index
The load index refers to how much weight a tire can carry. If your tire has a load index of
82, locate that number on the chart below, and then look to the right of it under Load (lbs).
You can see that your tire can support 1,047 pounds at maximum air pressure. Multiply that
by four to get your maximum load-carrying capacity. It is not recommended to install tires
with a lower load index than your factory stock tires.
- Speed Rating
This number corresponds to the maximum service speed for a tire. The U.S. government issues
speed ratings for tires based on how well they reach and sustain a specific speed.
A higher speed rating generally means that the tire will provide better handling.
For example: An H represents that the tire has a maximum service speed of 130 mph.
Never mix and match tires with different speed ratings on your vehicle. This may cause serious
handling problems.
Note: The speed rating relates only to tire speed capacity, and is NOT a recommendation
to exceed posted speed limits; always drive within the legal speed limits.
- DOT
Indicates the tire is compliant with all applicable safety standards established by the U.S.
Department of Transportation (DOT). This is followed by a tire identification or serial
number, which is a combination of numbers and letters up to 12 digits.
- UTQG
This indicates the Uniform Tire Quality Grading (UTQG), a quality rating system developed by the
DOT.
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