Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 275/50-21 | 285/45-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 31.83 (808.4) | 31.1 (789.9) | -0.73 (-18.5) -2.3% |
| Width inches (mm) | 10.83 (275) | 11.22 (285) | 0.39 (10) 3.6% |
| Circum. inches (mm) | 99.99 (2539.66) | 97.7 (2481.54) | -2.29 (-58.12) -2.3% |
| Sidewall Height inches (mm) | 5.41 (137.5) | 5.05 (128.25) | -0.36 (-9.25) -6.7% |
| Revolutions per mile (km) | 633.68 (393.75) | 648.53 (402.97) | 14.84 (9.22) 2.3% |
285/45-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.54 mph (31.45 km/h) |
| 25 mph (40.23 km/h) | 24.43 mph (39.31 km/h) |
| 30 mph (48.28 km/h) | 29.31 mph (47.18 km/h) |
| 35 mph (56.33 km/h) | 34.2 mph (55.04 km/h) |
| 40 mph (64.37 km/h) | 39.08 mph (62.9 km/h) |
| 45 mph (72.42 km/h) | 43.97 mph (70.76 km/h) |
| 50 mph (80.47 km/h) | 48.86 mph (78.63 km/h) |
| 55 mph (88.51 km/h) | 53.74 mph (86.49 km/h) |
| 60 mph (96.56 km/h) | 58.63 mph (94.35 km/h) |
| 65 mph (104.61 km/h) | 63.51 mph (102.21 km/h) |
| 70 mph (112.65 km/h) | 68.4 mph (110.08 km/h) |
| 75 mph (120.7 km/h) | 73.28 mph (117.94 km/h) |
| 80 mph (128.75 km/h) | 78.17 mph (125.8 km/h) |
| 85 mph (136.79 km/h) | 83.05 mph (133.66 km/h) |
| 90 mph (144.84 km/h) | 87.94 mph (141.53 km/h) |
| 95 mph (152.89 km/h) | 92.83 mph (149.39 km/h) |
| 100 mph (160.93 km/h) | 97.71 mph (157.25 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1650 | 1917 | 2065 | 2156 | 2254 | 2325 | 2402 | 2493 | 2620 | 2746 | 2886 | 2999 | 3202 | 3427 | 3603 | 3715 | 3778 | 4010 | 4333 | 5035 |
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