2013 Chevrolet Impala Owner Manual - Page 260

10-38 Vehicle Care UTQGS (Uniform Tire Quality Grading Standards): A tire information system that provides consumers with ratings for a tire's traction, temperature, and treadwear. Ratings are determined by tire manufacturers using government testing procedures. The ratings are molded into the sidewall of the tire. See Uniform Tire Quality Grading on page 10‑48. Vehicle Capacity Weight: The number of designated seating positions multiplied by 68 kg (150 lbs) plus the rated cargo load. See Vehicle Load Limits on page 9‑9. Vehicle Maximum Load on the Tire: Load on an individual tire due to curb weight, accessory weight, occupant weight, and cargo weight. Vehicle Placard: A label permanently attached to a vehicle showing the vehicle capacity weight and the original equipment tire size and recommended inflation pressure. See "Tire and Loading Information Label" under Vehicle Load Limits on page 9‑9. Rim: A metal support for a tire and upon which the tire beads are seated. Sidewall: The portion of a tire between the tread and the bead. Speed Rating: An alphanumeric code assigned to a tire indicating the maximum speed at which a tire can operate. Traction: The friction between the tire and the road surface. The amount of grip provided. Tread: The portion of a tire that comes into contact with the road. Treadwear Indicators: Narrow bands, sometimes called wear bars, that show across the tread of a tire when only 1.6 mm (1/16 in) of tread remains. See When It Is Time for New Tires on page 10‑45. Tire Pressure Tires need the correct amount of air pressure to operate effectively. Notice: Neither tire underinflation nor overinflation is good. Underinflated tires, or tires that do not have enough air, can result in: . Tire overloading and overheating which could lead to a blowout.