Frequently Asked Questions
Standard air pressure for this tire size is anywhere from 30-35 PSI when calculated cold. However, the actual pressure depends on the tire type and your vehicle’s specs which is why you should always consult your owner’s manual or doorframe placard before putting air in.
This tire size has a few close equivalents, such as 31x10.5R15 or LT235/75R15. Both these tires have a total diameter of around 31–32 inches when measured, and the tread width is 10–11 inches.
A 265/75R15 tire is roughly 31.6 inches in overall diameter and has a tread width of around 10.4 inches when mounted on a wheel and inflated. This size has a 75% aspect ratio, which means a 9.9-inch sidewall height from rim to tread.
For the most part, a 265/75R15 and a 31×10.5R15 tire are almost identical in diameter, tread width, and even load capacity. A 31x10.5R15 may be ever so slightly narrower on the tread, at 10.2 inches, compared to 10.4 inches on the 265/75R15.
The 75 on a tire size is the aspect ratio. This ratio is the tire’s sidewall height as a percentage of the tread width, meaning that the sidewall is 75% the size of the tread’s width. The “R” indicates the tire was built using radial construction, and finally, 15 means that the tire was made for the 15-inch wheel.
