Tires are their own special measurement hell. A 17 inch tire does not have a diameter of 17 inches. Those 17 inches are the diameter of the rim it's supposed to

Tires are their own special measurement hell. A 17 inch tire does not have a diameter of 17 inches. Those 17 inches are the diameter of the rim it's supposed to sit on[1]. Thus e.g. a 245/45 R17 tire has a diameter of around 26 inches. As you can deduct from the "simple" formula of: 245/10*45/100/2.54*2+17 =~ 25.7 I.e. the width is 245mm, the cross section of the tire is 45% of that, or ~110mm, multiply that by 2 and add the 17 inches and you've got the outer tire diameter. 1. https://www.moderntiredealer.com/8644/understanding-tire-dimensions https://www.moderntiredealer.com/8644/understanding-tire-dim...