Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 285/45-21 | 285/55-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 31.1 (789.9) | 33.34 (846.9) | 2.24 (57) 7.2% |
| Width inches (mm) | 11.22 (285) | 11.22 (285) | 0 (0) 0% |
| Circum. inches (mm) | 97.7 (2481.54) | 104.75 (2660.61) | 7.05 (179.07) 7.2% |
| Sidewall Height inches (mm) | 5.05 (128.25) | 6.17 (156.75) | 1.12 (28.5) 22.2% |
| Revolutions per mile (km) | 648.53 (402.97) | 604.88 (375.85) | -43.65 (-27.12) -6.7% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.44 mph (34.51 km/h) |
| 25 mph (40.23 km/h) | 26.8 mph (43.14 km/h) |
| 30 mph (48.28 km/h) | 32.16 mph (51.76 km/h) |
| 35 mph (56.33 km/h) | 37.53 mph (60.39 km/h) |
| 40 mph (64.37 km/h) | 42.89 mph (69.02 km/h) |
| 45 mph (72.42 km/h) | 48.25 mph (77.65 km/h) |
| 50 mph (80.47 km/h) | 53.61 mph (86.27 km/h) |
| 55 mph (88.51 km/h) | 58.97 mph (94.9 km/h) |
| 60 mph (96.56 km/h) | 64.33 mph (103.53 km/h) |
| 65 mph (104.61 km/h) | 69.69 mph (112.16 km/h) |
| 70 mph (112.65 km/h) | 75.05 mph (120.78 km/h) |
| 75 mph (120.7 km/h) | 80.41 mph (129.41 km/h) |
| 80 mph (128.75 km/h) | 85.77 mph (138.04 km/h) |
| 85 mph (136.79 km/h) | 91.13 mph (146.67 km/h) |
| 90 mph (144.84 km/h) | 96.49 mph (155.29 km/h) |
| 95 mph (152.89 km/h) | 101.86 mph (163.92 km/h) |
| 100 mph (160.93 km/h) | 107.22 mph (172.55 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1539 | 1788 | 1926 | 2011 | 2103 | 2168 | 2240 | 2325 | 2443 | 2561 | 2692 | 2797 | 2987 | 3196 | 3360 | 3465 | 3524 | 3740 | 4041 | 4696 |
Better Fuel Economy Factory Ratios Increased Power
