2009 Chevrolet Cobalt Owner's Manual - Page 313

Low-Profile Performance Tire If the vehicle has 225/40R18 size tires, they are classified as low-profile performance tires. These tires are designed for very responsive driving on wet or dry pavement. You may also notice more road noise with low-profile performance tires and that they tend to wear faster. The 225/40R18 tire is a high performance tire designed for dry traction and handling performance which may result in reduced tread life of 15,000 miles (24 140 km) or less depending on individual driving behavior. Notice: If the vehicle has low-profile tires, they are more susceptible to damage from road hazards or curb impact than standard profile tires. Tire and/or wheel assembly damage can occur when coming into contact with road hazards like, potholes, or sharp edged objects, or when sliding into a curb. The vehicle warranty does not cover this type of damage. Keep tires set to the correct inflation pressure and, when possible avoid contact with curbs, potholes, and other road hazards. Winter Tires If the vehicle has 225/40R18 size tires, they are classified as performance tires. These tires are designed for very responsive driving on wet or dry pavement. If you expect to drive on snow or ice covered roads often, you may want to get winter tires for the vehicle. All season tires provide good overall performance on most surfaces but they may not offer the traction you would like or the same level of performance as winter tires on snow or ice covered roads. Winter tires, in general, are designed for increased traction on snow and ice covered roads. With winter tires, there may be decreased dry road traction, increased road noise, and shorter tread life. After switching to winter tires, be alert for changes in vehicle handling and braking. See your dealer/retailer for details regarding winter tire availability and proper tire selection. Also, see Buying New Tires on page 5-72. 5-55