Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
140/60r18 vs 170/50r18 Tire Comparison Side By Side
  140/60-18 170/50-18 Difference
Diameter inches (mm) 24.61 (625.2) 24.69 (627.2) 0.08 (2) 0.3%
Width inches (mm) 5.51 (140) 6.69 (170) 1.18 (30) 21.4%
Circum. inches (mm) 77.33 (1964.12) 77.58 (1970.41) 0.25 (6.28) 0.3%
Sidewall Height inches (mm) 3.31 (84) 3.35 (85) 0.04 (1) 1.2%
Revolutions per mile (km) 819.37 (509.13) 816.76 (507.51) -2.61 (-1.62) -0.3%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.06 mph (32.29 km/h)
25 mph (40.23 km/h)25.08 mph (40.36 km/h)
30 mph (48.28 km/h)30.1 mph (48.43 km/h)
35 mph (56.33 km/h)35.11 mph (56.51 km/h)
40 mph (64.37 km/h)40.13 mph (64.58 km/h)
45 mph (72.42 km/h)45.14 mph (72.65 km/h)
50 mph (80.47 km/h)50.16 mph (80.72 km/h)
55 mph (88.51 km/h)55.18 mph (88.8 km/h)
60 mph (96.56 km/h)60.19 mph (96.87 km/h)
65 mph (104.61 km/h)65.21 mph (104.94 km/h)
70 mph (112.65 km/h)70.22 mph (113.01 km/h)
75 mph (120.7 km/h)75.24 mph (121.09 km/h)
80 mph (128.75 km/h)80.26 mph (129.16 km/h)
85 mph (136.79 km/h)85.27 mph (137.23 km/h)
90 mph (144.84 km/h)90.29 mph (145.3 km/h)
95 mph (152.89 km/h)95.3 mph (153.38 km/h)
100 mph (160.93 km/h)100.32 mph (161.45 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
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