Frequently Asked Questions
The overall height, or diameter, of a 285/70R18 tire is about 32.8 inches or 833 millimeters. It has a 285 millimeter tread width, sidewall height of 70% the tread width, and an 18-inch rim size. The tire’s relatively larger overall diameter enhances the ground clearance and off-road capability of an SUV or pickup truck.
The primary difference between 275/70R18 and 285/70R18 tires is the width of the tread, 285/70R18 has a tread width of 285mm, whereas the 275/70R18 tire measures in at 275mm. Both have similar heights of the sidewall, equal to 70% of the tread width and the same rim diameter of 18 inches.
Yes, 33-inch tires are normally bigger than 285 tires. The size of a 33-inch refers to the total diameter of the tire, including the width of the tread, the height of the sidewall, and the size of the rim. On the other hand, 285 tires, such as 285/70R18, refer to the width of the tread in millimeters. A 285/70R18 tire’s total diameter is roughly 32.8 inches and is marginally shorter than a 33-inch tire.
The number 285 in the tire size designation and is the tread width expressed in millimeters. A 285 tire has tread width of 285 millimeters, equivalent to 11.2 inches. Tread width is a critical tire dimension that determines the contact patch of the tire with the road surface and subsequently affects factors such as traction, stability, and load-carrying capacity.
