Tire Size Calculator

Tire Size Finder (optional):

Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
180/65r18 vs 285/85r18 Tire Comparison Side By Side
  180/65-18 285/85-18 Difference
Diameter inches (mm) 27.21 (691.2) 37.07 (941.7) 9.86 (250.5) 36.2%
Width inches (mm) 7.09 (180) 11.22 (285) 4.13 (105) 58.3%
Circum. inches (mm) 85.49 (2171.47) 116.47 (2958.44) 30.98 (786.97) 36.2%
Sidewall Height inches (mm) 4.61 (117) 9.54 (242.25) 4.93 (125.25) 107.1%
Revolutions per mile (km) 741.13 (460.52) 543.98 (338.02) -197.15 (-122.5) -26.6%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)27.25 mph (43.85 km/h)
25 mph (40.23 km/h)34.06 mph (54.81 km/h)
30 mph (48.28 km/h)40.87 mph (65.78 km/h)
35 mph (56.33 km/h)47.68 mph (76.74 km/h)
40 mph (64.37 km/h)54.5 mph (87.7 km/h)
45 mph (72.42 km/h)61.31 mph (98.67 km/h)
50 mph (80.47 km/h)68.12 mph (109.63 km/h)
55 mph (88.51 km/h)74.93 mph (120.59 km/h)
60 mph (96.56 km/h)81.74 mph (131.56 km/h)
65 mph (104.61 km/h)88.56 mph (142.52 km/h)
70 mph (112.65 km/h)95.37 mph (153.48 km/h)
75 mph (120.7 km/h)102.18 mph (164.44 km/h)
80 mph (128.75 km/h)108.99 mph (175.41 km/h)
85 mph (136.79 km/h)115.81 mph (186.37 km/h)
90 mph (144.84 km/h)122.62 mph (197.33 km/h)
95 mph (152.89 km/h)129.43 mph (208.3 km/h)
100 mph (160.93 km/h)136.24 mph (219.26 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
13841608173218081891195020152091219723032421251526862875302231163169336436354224
Better Fuel Economy Factory Ratios Increased Power

Most Popular 180/65-R18 Comparisons

To Top