Tire Designations

Tire Size

The following is an example of a typical passenger vehicle tire size.

(A) Passenger (P-Metric) Tire: The United States version of a metric tire sizing

(A) Passenger (P-Metric) Tire: The United States version of a metric tire sizing system. The letter P as the first character in the tire size means a passenger vehicle tire engineered to standards set by the U.S. Tire and Rim Association.

(B) Tire Width: The three-digit number indicates the tire section width in millimeters from sidewall to sidewall.

(C) Aspect Ratio: A two-digit number that indicates the tire height-to-width measurements. For example, if the tire size aspect ratio is 60, as shown in item C of the illustration, it would mean that the tire's sidewall is 60 percent as high as it is wide.

(D) Construction Code: A letter code is used to indicate the type of ply construction in the tire. The letter R means radial ply construction; the letter D means diagonal or bias ply construction; and the letter B means belted-bias ply construction.

(E) Rim Diameter: Diameter of the wheel in inches.

(F) Service Description: These characters represent the load index and speed rating of the tire. The load index represents the load carrying capacity a tire is certified to carry. The speed rating is the maximum speed a tire is certified to carry a load.

    See also:

    Windshield
    For safety, appearance, and the best viewing, keep the windshield clean and clear. • Signs of damage include scratches, cracks, and chips. • Trained dealer technicians can inspect the wi ...

    Managing the Vehicle Damage Repair Process
    In the event that your vehicle requires damage repairs, GM recommends that you take an active role in its repair. If you have a pre-determined repair facility of choice, take your vehicle there, ...

    Storing Name Tags
    The system can store up to 30 phone numbers as name tags that are shared between the Bluetooth and OnStar systems. The system uses the following commands to store and retrieve phone numbers: ► ...