Chevrolet Spark Owners Manual: Tire Designations
Tire Size
The following is an example of a typical passenger vehicle tire size.
(1) 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.
(2) Tire Width: The three-digit number indicates the tire section width in millimeters from sidewall to sidewall.
(3) 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 3 of the illustration, it would mean that the tire's sidewall is 60 percent as high as it is wide.
(4) 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.
(5) Rim Diameter: Diameter of the wheel in inches.
(6) 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.
Tire Sidewall Labeling
Useful information about a tire is molded into its sidewall. The examples show
a typical passenger tire sidewall.
Passenger (P-Metric) Tire Example
(1) Tire Size: The tire size is a combinatio ...
Tire Terminology and Definitions
Air Pressure: The amount of air inside the tire pressing outward on each square
inch of the tire. Air pressure is expressed in kPa (kilopascal) or psi (pounds per
square inch).
Accessory Weight: ...
Other materials:
If the On Indicator Is Lit for a Child Restraint
If a child restraint has been installed and the on indicator is lit:
Turn the vehicle off.
Remove the child restraint from the vehicle.
Remove any additional items from the seat such as blankets, cushions, seat
covers, seat heaters, or seat massagers.
Reinstall the child restraint follo ...
Warning Lights, Gauges, and Indicators
Warning lights and gauges can signal that something is wrong before it becomes
serious enough to cause an expensive repair or replacement. Paying attention to
the warning lights and gauges could prevent injury.
Warning lights come on when there could be a problem with a vehicle function.
Some ...
Reporting Safety Defects to the United States Government
If you believe that your vehicle has a defect which could cause a crash or could
cause injury or death, you should immediately inform the National Highway Traffic
Safety Administration (NHTSA) in addition to notifying General Motors.
If NHTSA receives similar complaints, it may open an investig ...
