Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 275/40-21 | 285/45-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 29.66 (753.4) | 31.1 (789.9) | 1.44 (36.5) 4.8% |
| Width inches (mm) | 10.83 (275) | 11.22 (285) | 0.39 (10) 3.6% |
| Circum. inches (mm) | 93.18 (2366.88) | 97.7 (2481.54) | 4.51 (114.67) 4.8% |
| Sidewall Height inches (mm) | 4.33 (110) | 5.05 (128.25) | 0.72 (18.25) 16.6% |
| Revolutions per mile (km) | 679.94 (422.5) | 648.53 (402.97) | -31.42 (-19.52) -4.6% |
285/45-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.97 mph (33.75 km/h) |
| 25 mph (40.23 km/h) | 26.21 mph (42.18 km/h) |
| 30 mph (48.28 km/h) | 31.45 mph (50.62 km/h) |
| 35 mph (56.33 km/h) | 36.7 mph (59.06 km/h) |
| 40 mph (64.37 km/h) | 41.94 mph (67.49 km/h) |
| 45 mph (72.42 km/h) | 47.18 mph (75.93 km/h) |
| 50 mph (80.47 km/h) | 52.42 mph (84.37 km/h) |
| 55 mph (88.51 km/h) | 57.66 mph (92.8 km/h) |
| 60 mph (96.56 km/h) | 62.91 mph (101.24 km/h) |
| 65 mph (104.61 km/h) | 68.15 mph (109.68 km/h) |
| 70 mph (112.65 km/h) | 73.39 mph (118.11 km/h) |
| 75 mph (120.7 km/h) | 78.63 mph (126.55 km/h) |
| 80 mph (128.75 km/h) | 83.88 mph (134.99 km/h) |
| 85 mph (136.79 km/h) | 89.12 mph (143.42 km/h) |
| 90 mph (144.84 km/h) | 94.36 mph (151.86 km/h) |
| 95 mph (152.89 km/h) | 99.6 mph (160.29 km/h) |
| 100 mph (160.93 km/h) | 104.84 mph (168.73 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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