2009 Chevrolet Cobalt Owner's Manual - Page 316

(B) Tire Ply Material: The type of cord and number of plies in the sidewall and under the tread. (C) Tire Identification Number (TIN): The letters and numbers following the DOT (Department of Transportation) code is the Tire Identification Number (TIN). The TIN shows the manufacturer and plant code, tire size, and date the tire was manufactured. The TIN is molded onto both sides of the tire, although only one side may have the date of manufacture. (D) Maximum Cold Inflation Load Limit: Maximum load that can be carried and the maximum pressure needed to support that load. (E) Tire Inflation: The temporary use tire or compact spare tire should be inflated to 60 psi (420 kPa). For more information on tire pressure and inflation see Inflation - Tire Pressure on page 5-62. (F) Tire Size : A combination of letters and numbers define a tire's width, height, aspect ratio, construction type and service description. The letter T as the first character in the tire size means the tire is for temporary use only. Compact Spare Tire Example (A) Temporary Use Only: The compact spare tire or temporary use tire has a tread life of approximately 3,000 miles (5 000 km) and should not be driven at speeds over 65 mph (105 km/h). The compact spare tire is for emergency use when a regular road tire has lost air and gone flat. If your vehicle has a compact spare tire, see Compact Spare Tire on page 5-109 and If a Tire Goes Flat on page 5-79. 5-58