Tire Size Calculator

Tire Size Finder (optional):

Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
135/80r18 vs 145/60r20 Tire Comparison Side By Side
  135/80-18 145/60-20 Difference
Diameter inches (mm) 26.5 (673.2) 26.85 (682) 0.35 (8.8) 1.3%
Width inches (mm) 5.31 (135) 5.71 (145) 0.39 (10) 7.4%
Circum. inches (mm) 83.26 (2114.92) 84.35 (2142.57) 1.09 (27.65) 1.3%
Sidewall Height inches (mm) 4.25 (108) 3.43 (87) -0.83 (-21) -19.4%
Revolutions per mile (km) 760.95 (472.83) 751.13 (466.73) -9.82 (-6.1) -1.3%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.26 mph (32.61 km/h)
25 mph (40.23 km/h)25.33 mph (40.76 km/h)
30 mph (48.28 km/h)30.39 mph (48.91 km/h)
35 mph (56.33 km/h)35.46 mph (57.06 km/h)
40 mph (64.37 km/h)40.52 mph (65.22 km/h)
45 mph (72.42 km/h)45.59 mph (73.37 km/h)
50 mph (80.47 km/h)50.65 mph (81.52 km/h)
55 mph (88.51 km/h)55.72 mph (89.67 km/h)
60 mph (96.56 km/h)60.78 mph (97.82 km/h)
65 mph (104.61 km/h)65.85 mph (105.97 km/h)
70 mph (112.65 km/h)70.92 mph (114.13 km/h)
75 mph (120.7 km/h)75.98 mph (122.28 km/h)
80 mph (128.75 km/h)81.05 mph (130.43 km/h)
85 mph (136.79 km/h)86.11 mph (138.58 km/h)
90 mph (144.84 km/h)91.18 mph (146.73 km/h)
95 mph (152.89 km/h)96.24 mph (154.89 km/h)
100 mph (160.93 km/h)101.31 mph (163.04 km/h)

Gear Ratio / RPMs for New Tire (@ 65 mph)
2.35 2.73 2.94 3.07 3.21 3.31 3.42 3.55 3.73 3.91 4.11 4.27 4.56 4.88 5.13 5.29 5.38 5.71 6.17 7.17
19112221239124972611269227822888303431803343347337093969417343034376464450195832
Better Fuel Economy Factory Ratios Increased Power

Most Popular 135/80-R18 Comparisons

To Top