Diesel Data: Automotive Repair

Tire Description

Caution: Do not mix different types of tires on the same vehicle such as radial, bias, and bias-belted tires except in emergencies because vehicle handling may be seriously affected and may result in loss of control and possible serious injury.

This vehicle is equipped with speed rated tires. Listed below are the common speed rating symbols and the corresponding maximum speeds:





A Tire Performance Criteria (TPC) specification number is molded in the sidewall near the tire size of all original equipment tires. Usually, a specific TPC number is assigned to each tire size. The TPC specification number assures that the tire meets the following GM's performance standards.
^ Meets the standards for traction.
^ Meets the standards for endurance.
^ Meets the standards for dimension.
^ Meets the standards for noise.
^ Meets the standards for handling.
^ Meets the standards for rolling resistance, and others.

The following is required of replacement tires:
^ Replacement tires must be of the same size as the original tires.
^ Replacement tires must be of the same speed rating as the original tires.
^ Replacement tires must be of the same load index as the original tires.
^ Replacement tires must be of the same construction as the original tires.
^ Replacement tires must have the same TPC specification number as the original tires.

The following may seriously be affected by the use of any other tire size, tire speed rating or tire type:
^ May seriously affect the ride.
^ May seriously affect the handling.
^ May seriously affect the speedometer/odometer calibration.
^ May seriously affect the antilock brake system.
^ May seriously affect the vehicle ground clearance.
^ May seriously affect the trailering capacity.
^ May seriously affect the tire clearance to the body.
^ May seriously affect the tire clearance to the chassis.