Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 225/45-21 | 255/55-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.97 (735.9) | 31.04 (788.5) | 2.07 (52.6) 7.1% |
| Width inches (mm) | 8.86 (225) | 10.04 (255) | 1.18 (30) 13.3% |
| Circum. inches (mm) | 91.02 (2311.9) | 97.53 (2477.15) | 6.51 (165.25) 7.1% |
| Sidewall Height inches (mm) | 3.99 (101.25) | 5.52 (140.25) | 1.54 (39) 38.5% |
| Revolutions per mile (km) | 696.11 (432.54) | 649.68 (403.69) | -46.44 (-28.85) -6.7% |
255/55-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.43 mph (34.49 km/h) |
| 25 mph (40.23 km/h) | 26.79 mph (43.11 km/h) |
| 30 mph (48.28 km/h) | 32.14 mph (51.73 km/h) |
| 35 mph (56.33 km/h) | 37.5 mph (60.35 km/h) |
| 40 mph (64.37 km/h) | 42.86 mph (68.98 km/h) |
| 45 mph (72.42 km/h) | 48.22 mph (77.6 km/h) |
| 50 mph (80.47 km/h) | 53.57 mph (86.22 km/h) |
| 55 mph (88.51 km/h) | 58.93 mph (94.84 km/h) |
| 60 mph (96.56 km/h) | 64.29 mph (103.46 km/h) |
| 65 mph (104.61 km/h) | 69.65 mph (112.08 km/h) |
| 70 mph (112.65 km/h) | 75 mph (120.71 km/h) |
| 75 mph (120.7 km/h) | 80.36 mph (129.33 km/h) |
| 80 mph (128.75 km/h) | 85.72 mph (137.95 km/h) |
| 85 mph (136.79 km/h) | 91.08 mph (146.57 km/h) |
| 90 mph (144.84 km/h) | 96.43 mph (155.19 km/h) |
| 95 mph (152.89 km/h) | 101.79 mph (163.82 km/h) |
| 100 mph (160.93 km/h) | 107.15 mph (172.44 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1653 | 1921 | 2068 | 2160 | 2258 | 2329 | 2406 | 2498 | 2624 | 2751 | 2892 | 3004 | 3208 | 3433 | 3609 | 3722 | 3785 | 4017 | 4341 | 5044 |
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