Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 285/45-21 | 285/50-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 31.1 (789.9) | 31.22 (793) | 0.12 (3.1) 0.4% |
| Width inches (mm) | 11.22 (285) | 11.22 (285) | 0 (0) 0% |
| Circum. inches (mm) | 97.7 (2481.54) | 98.08 (2491.28) | 0.38 (9.74) 0.4% |
| Sidewall Height inches (mm) | 5.05 (128.25) | 5.61 (142.5) | 0.56 (14.25) 11.1% |
| Revolutions per mile (km) | 648.53 (402.97) | 645.99 (401.4) | -2.54 (-1.58) -0.4% |
285/50-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.08 mph (32.31 km/h) |
| 25 mph (40.23 km/h) | 25.1 mph (40.39 km/h) |
| 30 mph (48.28 km/h) | 30.12 mph (48.47 km/h) |
| 35 mph (56.33 km/h) | 35.14 mph (56.55 km/h) |
| 40 mph (64.37 km/h) | 40.16 mph (64.63 km/h) |
| 45 mph (72.42 km/h) | 45.18 mph (72.7 km/h) |
| 50 mph (80.47 km/h) | 50.2 mph (80.78 km/h) |
| 55 mph (88.51 km/h) | 55.22 mph (88.86 km/h) |
| 60 mph (96.56 km/h) | 60.24 mph (96.94 km/h) |
| 65 mph (104.61 km/h) | 65.26 mph (105.02 km/h) |
| 70 mph (112.65 km/h) | 70.27 mph (113.1 km/h) |
| 75 mph (120.7 km/h) | 75.29 mph (121.17 km/h) |
| 80 mph (128.75 km/h) | 80.31 mph (129.25 km/h) |
| 85 mph (136.79 km/h) | 85.33 mph (137.33 km/h) |
| 90 mph (144.84 km/h) | 90.35 mph (145.41 km/h) |
| 95 mph (152.89 km/h) | 95.37 mph (153.49 km/h) |
| 100 mph (160.93 km/h) | 100.39 mph (161.57 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1644 | 1910 | 2057 | 2148 | 2246 | 2315 | 2392 | 2483 | 2609 | 2735 | 2875 | 2987 | 3190 | 3414 | 3589 | 3701 | 3764 | 3994 | 4316 | 5016 |
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