Irregular and premature tire wear has many causes, the most common being incorrect cold tire inflation pressure, incorrect wheel alignment, lack of tire rotation and worn suspension parts. These conditions can often be diagnosed by visually inspecting the tire tread for the following telltale symptoms:

Tread wear at center of tire - over-inflation.

Tread wear on edges of tire - under-inflation.

The original equipment tires specified for Saturn vehicles have built in tread wear indicators to warn when tires need replacement. These indicators are wide bands located beneath the tread surface at the maximum tread wear depth. Tires are determined to be worn when indicator band appears across 2 or more tread grooves at 3 locations about the circumference of the tire.