Issue link: http://read.dmtmag.com/i/34501
TRUCK TIRE SIZE MARKINGS Most truck tire sizes are indicated by the section width in inches, followed by R for radial (dash (-) designates the diagonal (bias or cross) construction), followed by the rim or wheel diameter in inches: TUBE-TYPE 10.00R20 10.00 = nominal section width in inches R = radial 20 = rim or wheel diameter in inches TUBELESS 11R22.5 11 = nominal section width in inches R = radial 22.5 = rim or wheel diameter in inches Note: A “rule-of-thumb” formula for finding equivalent tubeless sizes from tube-type: Take the nominal section width and remove all figures after the decimal point. Round up to next whole nominal section number and add 2.5 to rim diameter. Example: TUBE-TYPE TUBELESS 8.25R20 = 9R22.5 Nominal Cross Section 8.25 Remove .25 Add Rim Diameter 1 to the 8 = 9 20 Add 2.5 to Rim Diameter 20 + 2.5 Thus we have 9R22.5 Tubeless. = 22.5 Tube-Type Tubeless 20" 22.5" COMPARATIVE SIZES – STANDARD – LOW PROFILE TUBE-TYPE TUBELESS TYPE MICHELIN 8.25R15 8.25R20 9.00R20 10.00R20 11.00R20 10.00R22 11.00R22 ® 9R17.5 9R22.5 235/80R22.5 245/75R22.5 10R22.5 255/80R22.5 265/75R22.5 11R22.5 275/80R22.5 295/75R22.5 12R22.5 11R24.5 12R24.5 275/80R24.5 285/75R24.5 * The Tire and Rim Association, Inc. REPAIR AND RETREAD 1. Follow proper procedures per your Michelin Retread Technologies dealer. 2. Use bias repair units in bias tires and radial repair units in radial tires. 3. When performing tube repairs, do not install the patch on an inflated tube, and apply a tire talc to the patch and buffed area to prevent sticking to the inside of the tire. TRA* Section Seven: Diagonal (Bias or Cross) Ply and Tube-Type 91