Frequently Asked Questions
Standard air pressure for this tire size is anywhere from 30-50 PSI when it is calculated cold before hitting the road. However, the precise optimal pressure depends upon the tire type and your vehicle’s specs.
This tire size has very close actual equivalents, such as 31x10.5R15 or LT235/75R15. All these tires have a total diameter of about 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 on the road. This size has a sizable 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 ultimate diameter, tread width, and even load capacity. A 31×10.5R15 may be ever so slightly narrower on the tread, at 10.2 inches as 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. In other words, the sidewall is 75% the size of the tread’s width. The “R” indicates the tire was built using radial construction, and finally, the tire was made for the 15-inch wheel.
