What does 235 mean on a tire?
R stands for radial construction which refers to how the tires are made. Following the slash, the next number in the sequence is “45. This number is the tire’s aspect ratio – essentially the height of the tire’s profile outward from the rim represented as a percentage of the tire’s width. We calculate this number by dividing the tire’s section height by the tire’s section width.On a tire with an aspect ratio (profile) of 65, the sidewall’s height is 65 percent of the tire’s width. Fifty and 45 would be considered low-profile, and would have a shorter sidewall.