Tire Size Calculator

Tire Size Finder (optional):

Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
90/90r18 vs 120/80r18 Tire Comparison Side By Side
  90/90-18 120/80-18 Difference
Diameter inches (mm) 24.38 (619.2) 25.56 (649.2) 1.18 (30) 4.8%
Width inches (mm) 3.54 (90) 4.72 (120) 1.18 (30) 33.3%
Circum. inches (mm) 76.59 (1945.27) 80.3 (2039.52) 3.71 (94.25) 4.8%
Sidewall Height inches (mm) 3.19 (81) 3.78 (96) 0.59 (15) 18.5%
Revolutions per mile (km) 827.31 (514.07) 789.08 (490.31) -38.23 (-23.76) -4.6%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.97 mph (33.75 km/h)
25 mph (40.23 km/h)26.21 mph (42.18 km/h)
30 mph (48.28 km/h)31.45 mph (50.62 km/h)
35 mph (56.33 km/h)36.7 mph (59.06 km/h)
40 mph (64.37 km/h)41.94 mph (67.49 km/h)
45 mph (72.42 km/h)47.18 mph (75.93 km/h)
50 mph (80.47 km/h)52.42 mph (84.37 km/h)
55 mph (88.51 km/h)57.66 mph (92.8 km/h)
60 mph (96.56 km/h)62.91 mph (101.24 km/h)
65 mph (104.61 km/h)68.15 mph (109.68 km/h)
70 mph (112.65 km/h)73.39 mph (118.11 km/h)
75 mph (120.7 km/h)78.63 mph (126.55 km/h)
80 mph (128.75 km/h)83.88 mph (134.99 km/h)
85 mph (136.79 km/h)89.12 mph (143.42 km/h)
90 mph (144.84 km/h)94.36 mph (151.86 km/h)
95 mph (152.89 km/h)99.6 mph (160.3 km/h)
100 mph (160.93 km/h)104.84 mph (168.73 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
20082333251226232743282829223033318733413512364938964170438445204597487952726127
Better Fuel Economy Factory Ratios Increased Power

Most Popular 90/90-R18 Comparisons

To Top