Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 225/45-21 | 255/45-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.97 (735.9) | 29.04 (737.5) | 0.06 (1.6) 0.2% |
| Width inches (mm) | 8.86 (225) | 10.04 (255) | 1.18 (30) 13.3% |
| Circum. inches (mm) | 91.02 (2311.9) | 91.22 (2316.92) | 0.2 (5.03) 0.2% |
| Sidewall Height inches (mm) | 3.99 (101.25) | 4.52 (114.75) | 0.53 (13.5) 13.3% |
| Revolutions per mile (km) | 696.11 (432.54) | 694.6 (431.61) | -1.51 (-0.94) -0.2% |
255/45-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.04 mph (32.26 km/h) |
| 25 mph (40.23 km/h) | 25.05 mph (40.32 km/h) |
| 30 mph (48.28 km/h) | 30.07 mph (48.39 km/h) |
| 35 mph (56.33 km/h) | 35.08 mph (56.45 km/h) |
| 40 mph (64.37 km/h) | 40.09 mph (64.51 km/h) |
| 45 mph (72.42 km/h) | 45.1 mph (72.58 km/h) |
| 50 mph (80.47 km/h) | 50.11 mph (80.64 km/h) |
| 55 mph (88.51 km/h) | 55.12 mph (88.71 km/h) |
| 60 mph (96.56 km/h) | 60.13 mph (96.77 km/h) |
| 65 mph (104.61 km/h) | 65.14 mph (104.83 km/h) |
| 70 mph (112.65 km/h) | 70.15 mph (112.9 km/h) |
| 75 mph (120.7 km/h) | 75.16 mph (120.96 km/h) |
| 80 mph (128.75 km/h) | 80.17 mph (129.03 km/h) |
| 85 mph (136.79 km/h) | 85.18 mph (137.09 km/h) |
| 90 mph (144.84 km/h) | 90.2 mph (145.16 km/h) |
| 95 mph (152.89 km/h) | 95.21 mph (153.22 km/h) |
| 100 mph (160.93 km/h) | 100.22 mph (161.28 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1768 | 2053 | 2211 | 2309 | 2415 | 2490 | 2572 | 2670 | 2806 | 2941 | 3091 | 3212 | 3430 | 3671 | 3859 | 3979 | 4047 | 4295 | 4641 | 5393 |
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