Where do I find my tire size?
To find your original equipment tire size, load carrying capacity, speed rating and PSI (cold) inflation specifications, check your vehicles’ placard.
Where is the placard located?
If you have a newer vehicle, the placard is located in the driver’s side doorjamb. If you have an older vehicle, look for the placard in the rear doorjamb, glove box, under the hood, in the fuel door or in your owner’s manual.
How do I read my tire size on the placard?
The following diagram illustrates some of the important aspects of your tire size:
Metric Type (P)
The “P” indicates the tire is for passenger vehicles. “LT” would indicate a light truck tire. The “P” indicates the tire is for passenger vehicles. “LT” would indicate a light truck tire.
This three-digit number gives the width in millimeters of the tire from sidewall edge to sidewall edge. In general, the larger the number, the wider the tire.
Aspect Ratio (65)
The two-digit number, know as the aspect ratio, gives the tire’s ratio of height to width. Numbers of 70 or lower indicate a short sidewall for improved steering response and better overall handling on dry pavement.
Construction Type (R)
The “R” stands for the radial. Radial ply construction of tires has been the industry standard for the past 20 years.
Rim Size (15)
This two-digit number is the wheel or rim size’s diameter in inches. If you change your wheel size, you will have to purchase new tires to match the new wheel size.
Source: safercar.gov. The placard is only an example. Your vehicle placard may look different.