Latest 47++ 315 75 17 Tires. Alibaba.com offers 908 315 75 17.5 products. A wide variety of 315 75 17.5 options are available to you, such as certification, width, and type. Metric to standard conversion enter the metric size (i.e. Using the example numbers the tires aspect ratio would calculate as 215x.65=139.75 where 139.75 is the tires height in millimeters. 315 75 17 Tires - 305 70 16 305 70 17 Or 315 75 16 F150online Forums 315/70r17 tires have a diameter of 34.