The tire sidewall is the section between the tread and the bead. It flexes as the tire rolls, protects the internal structure and displays important information about size, construction and ratings.
What the sidewall means
The sidewall is made from rubber compounds reinforced by the tire’s body plies. Unlike the tread, it is not designed to contact the road during normal driving. Its height depends partly on the tire’s aspect ratio, while its stiffness influences steering response, ride comfort and impact absorption.
What the markings show
Typical sidewall markings include tire size, load index, speed rating, construction type, manufacturing code and maximum inflation information. Some tires also display rotation arrows, inside/outside mounting labels or severe-snow-service symbols.
Why sidewall condition matters
Cuts, exposed cords, bulges and cracking can indicate structural damage. A bulge may mean internal cords have been weakened by an impact. Because sidewall damage is generally not repaired like a simple tread puncture, a qualified tire professional should inspect any suspicious area.
Related terms
Bead, aspect ratio, load index and tire pressure.
