Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 40/12.5-20 | 285/55-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 40.03 (1016.8) | 32.34 (821.5) | -7.69 (-195.3) -19.2% |
| Width inches (mm) | 12.52 (318) | 11.22 (285) | -1.3 (-33) -10.4% |
| Circum. inches (mm) | 125.76 (3194.37) | 101.61 (2580.82) | -24.16 (-613.55) -19.2% |
| Sidewall Height inches (mm) | 10.02 (254.4) | 6.17 (156.75) | -3.84 (-97.65) -38.4% |
| Revolutions per mile (km) | 503.81 (313.05) | 623.58 (387.47) | 119.77 (74.42) 23.8% |
285/55-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 16.16 mph (26 km/h) |
| 25 mph (40.23 km/h) | 20.2 mph (32.51 km/h) |
| 30 mph (48.28 km/h) | 24.24 mph (39.01 km/h) |
| 35 mph (56.33 km/h) | 28.28 mph (45.51 km/h) |
| 40 mph (64.37 km/h) | 32.32 mph (52.01 km/h) |
| 45 mph (72.42 km/h) | 36.36 mph (58.51 km/h) |
| 50 mph (80.47 km/h) | 40.4 mph (65.01 km/h) |
| 55 mph (88.51 km/h) | 44.44 mph (71.51 km/h) |
| 60 mph (96.56 km/h) | 48.48 mph (78.01 km/h) |
| 65 mph (104.61 km/h) | 52.52 mph (84.52 km/h) |
| 70 mph (112.65 km/h) | 56.55 mph (91.02 km/h) |
| 75 mph (120.7 km/h) | 60.59 mph (97.52 km/h) |
| 80 mph (128.75 km/h) | 64.63 mph (104.02 km/h) |
| 85 mph (136.79 km/h) | 68.67 mph (110.52 km/h) |
| 90 mph (144.84 km/h) | 72.71 mph (117.02 km/h) |
| 95 mph (152.89 km/h) | 76.75 mph (123.52 km/h) |
| 100 mph (160.93 km/h) | 80.79 mph (130.02 km/h) |
| 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1587 | 1843 | 1985 | 2073 | 2168 | 2235 | 2309 | 2397 | 2519 | 2640 | 2775 | 2883 | 3079 | 3295 | 3464 | 3572 | 3633 | 3856 | 4166 | 4842 |
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