14 tire lines. 275/45R21 tires sized to your wheels and your car.
A 275/45R21 is 275 mm wide with a 124 mm sidewall (45 series) on a 21 inch wheel, 30.7 inches tall overall. A tire size only makes sense next to a wheel width and a car. 275/45R21 mounts on a range of widths, and the overall height decides whether the speedometer and the fender stay happy.
14 lines carry 275/45R21, from 5 brands (Michelin, Pirelli, Toyo, Continental Tire and 1 more). By type that is 7 all season, 6 performance summer and 1 highway. The tire has to stay near your car's stock height and mount on your wheel width, so pick the car and the wheel set and the page keeps only the 275/45R21 lines that do both.













