For 1990-2009 cars

# INFORMATION ON SPEED RATED TIRES

#### SUBJECT: INFORMATION ON SPEED RATED TIRES

#### MODELS: 1995 AND PRIOR YEAR PASSENGER CARS AND LIGHT DUTY TRUCKS

ALL ORIGINAL EQUIPMENT PASSENGER CAR AND LIGHT DUTY TRUCK TIRES USED BY GENERAL MOTORS HAVE A SPEED RATING SYMBOL MOLDED ON THEIR SIDEWALL. THIS SPEED SYMBOL, ALONG WITH THE TIRE'S LOAD INDEX, MAKE UP THE SERVICE DESCRIPTION THAT FOLLOWS THE TIRE'S SIZE. THE ORIGINAL EQUIPMENT TIRE SIZE, SPEED RATING, AND RECOMMENDED INFLATION PRESSURE ARE LISTED ON THE TIRE PLACARD USUALLY LOCATED ON THE DRIVER'S DOOR EDGE. WHEN REPLACING TIRES, NEVER INSTALL A TIRE THAT IS A SMALLER SIZE OR LESSER SPEED RATING THAN THAT USED AS ORIGINAL EQUIPMENT. AS IN THE PAST, IT IS RECOMMENDED THAT REPLACEMENT TIRES HAVE A TPC (TIRE PERFORMANCE CRITERIA) NUMBER ON THE SIDEWALL THAT IS IDENTICAL TO THAT ON THE ORIGINAL TIRES.

COMMON SPEED RATING ON TIRES USED BY GENERAL MOTORS ARE AS FOLLOWS:

MAXIMUM MAXIMUM SPEED SYMBOL SPEED (KM/H) SPEED (MPH) ============ ============= ===========

S 180 112 T 190 118 U 200 124 H 210 130 V 240 149 Z OVER 240 OVER 149

#### IMPORTANT: MOST BASE ALL SEASON TIRES AND TOURING TIRES USED BY GM ARE S RATED. PERFORMANCE TIRES WILL USUALLY HAVE A HIGHER SPEED RATING. HIGH PERFORMANCE TIRES ARE USUALLY Z RATED. Z RATED TIRES CARRY THE Z SYMBOL WITHIN THE TIRE SIZE, RATHER THAN AFTER THE SIZE IN THE SERVICE DESCRIPTION.

THESE SPEEDS APPLY ONLY AT THE TIRE'S FULL PRESSURE. AN UNDERINFLATED TIRE WILL NOT MEET ITS SPEED RATING CAPABILITY.

FIGURES: 0

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION. SEE A GENERAL MOTORS DEALER SERVICING YOUR BRAND OF GENERAL MOTORS VEHICLE FOR INFORMATION ON WHETHER YOUR VEHICLE MAY BENEFIT FROM THE INFORMATION.

COPYRIGHT 1994 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.