Tire Size Calculator

Tire Size Finder (optional):

Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
215/30r20 vs 225/30r18 Tire Comparison Side By Side
  215/30-20 225/30-18 Difference
Diameter inches (mm) 25.08 (637) 23.31 (592.2) -1.76 (-44.8) -7%
Width inches (mm) 8.46 (215) 8.86 (225) 0.39 (10) 4.7%
Circum. inches (mm) 78.79 (2001.19) 73.25 (1860.45) -5.54 (-140.74) -7%
Sidewall Height inches (mm) 2.54 (64.5) 2.66 (67.5) 0.12 (3) 4.7%
Revolutions per mile (km) 804.19 (499.7) 865.03 (537.5) 60.84 (37.8) 7.6%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)18.59 mph (29.92 km/h)
25 mph (40.23 km/h)23.24 mph (37.4 km/h)
30 mph (48.28 km/h)27.89 mph (44.88 km/h)
35 mph (56.33 km/h)32.54 mph (52.37 km/h)
40 mph (64.37 km/h)37.19 mph (59.85 km/h)
45 mph (72.42 km/h)41.84 mph (67.33 km/h)
50 mph (80.47 km/h)46.48 mph (74.81 km/h)
55 mph (88.51 km/h)51.13 mph (82.29 km/h)
60 mph (96.56 km/h)55.78 mph (89.77 km/h)
65 mph (104.61 km/h)60.43 mph (97.25 km/h)
70 mph (112.65 km/h)65.08 mph (104.73 km/h)
75 mph (120.7 km/h)69.73 mph (112.21 km/h)
80 mph (128.75 km/h)74.37 mph (119.69 km/h)
85 mph (136.79 km/h)79.02 mph (127.17 km/h)
90 mph (144.84 km/h)83.67 mph (134.65 km/h)
95 mph (152.89 km/h)88.32 mph (142.14 km/h)
100 mph (160.93 km/h)92.97 mph (149.62 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
22012557275428763007310132043325349436633850400042724571480549555040534957806716
Better Fuel Economy Factory Ratios Increased Power

Most Popular 215/30-R20 Comparisons

To Top