Which tire is taller, 265 or 275?
In a 265/70r18 tire, the sidewall height is 70% of 265mm, but in a 275/65r18 tire, it is only 65% of 275mm. This makes 265/70r18 to have a taller relative sidewall and therefore makes the total diameter slightly larger. Tire diameter can vary slightly for each tire model. The listed diameters are from calculations based on the tire size. When changing tire sizes, we recommend staying within 3% of the diameter/height of the original tire.As a general rule, you want replacement tires that are within 3 percent of the diameter (height) measurement of the tires originally on your vehicle.