|MARK’S CORNER – AUTO REPAIR HELP|
SUSPENSION AND TIRES
Other information that can be found on the tire side wall is the Uniform Tire Quality Grading designation. This is a government tire rating system used by manufacturers to provide tire comparison information. With the UTQG rating system, information is given to compare tire treadwear, traction and temperature resistance. Treadwear is a measure of tire durability. 100 would be a tire rated for standard resistance to treadwear. A rating of 300 would be a tire with three times the treadwear resistance of a standard tire. This rating should be used to compare tire treadwear within a manufacturer, not between manufacturers.
The traction rating is a grade classifying a tires ability to stop in a straight line on wet surfaces, concrete and asphalt under test conditions. An A rating means the tire meets maximum DOT standards. A B rating means the tire meets medium DOT requirements. A C rating indicates a tire meets minimum requirements. There are three grades used to measure a tires resistance to generation of heat due to friction. Grade A indicates a tire that can withstand temperatures generated at 115 mph for 30 minutes. Grade B indicates a tire that can withstand temperatures generated at 100 mph for 30 minutes. Grade C indicates a tire that cannot withstand temperatures generated at 100 mph for 30 minutes.
Tire wear is affected by driving conditions, wheel alignment, balance and inflation pressure. Proper maintenance is the best way to insure longer tire life. Inflation pressure should be checked weekly. Tire rotation schedules should be followed as recommended by the manufacturer. Wheel alignment should be checked if uneven tire wear is noticed or after running over a large hole or object. Aggressive driving should be avoided to extend tire life as well.
(Mark gave up on sports when the Browns left Cleveland and now spends his Sundays working under a shade tree in the back yard tuning his son’s soap box derby car.)