Traction: The friction between the tire and the roadsurface. The amount of grip provided.Tread: The portion of a tire that comes into contactwith the road.Treadwear Indicators: Narrow bands, sometimescalled “wear bars,” that show across the tread of a tirewhen only 1/16 inch (1.6 mm) of tread remains.See When It Is Time for New Tires on page 5-64.UTQGS (Uniform Tire Quality Grading Standards):A tire information system that provides consumerswith ratings for a tire’s traction, temperature, andtreadwear. Ratings are determined by tire manufacturersusing government testing procedures. The ratings aremolded into the sidewall of the tire. See UniformTire Quality Grading on page 5-66.Vehicle Capacity Weight: The number of designatedseating positions multiplied by 150 lbs (68 kg) plusthe rated cargo load. See Loading Your Vehicleon page 4-45.Vehicle Maximum Load on the Tire: Load on anindividual tire due to curb weight, accessory weight,occupant weight, and cargo weight.Vehicle Placard: A label permanently attached to avehicle showing the original equipment tire sizeand recommended inflation pressure. See Loading YourVehicle on page 4-45.Inflation - Tire PressureTires need the correct amount of air pressure tooperate effectively.Notice: Do not let anyone tell you thatunder-inflation or over-inflation is all right. It is not.If your tires do not have enough air (under-inflation),you can get the following:• Too much flexing• Too much heat• Tire overloading• Premature or irregular wear• Poor handling• Reduced fuel economyIf your tires have too much air (over-inflation),you can get the following:• Unusual wear• Poor handling• Rough ride• Needless damage from road hazards5-58
