Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 255/45-20 | 285/40-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 29.04 (737.5) | 28.98 (736) | -0.06 (-1.5) -0.2% |
| Width inches (mm) | 10.04 (255) | 11.22 (285) | 1.18 (30) 11.8% |
| Circum. inches (mm) | 91.22 (2316.92) | 91.03 (2312.21) | -0.19 (-4.71) -0.2% |
| Sidewall Height inches (mm) | 4.52 (114.75) | 4.49 (114) | -0.03 (-0.75) -0.7% |
| Revolutions per mile (km) | 694.6 (431.61) | 696.02 (432.49) | 1.42 (0.88) 0.2% |
285/40-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.96 mph (32.12 km/h) |
| 25 mph (40.23 km/h) | 24.95 mph (40.15 km/h) |
| 30 mph (48.28 km/h) | 29.94 mph (48.18 km/h) |
| 35 mph (56.33 km/h) | 34.93 mph (56.21 km/h) |
| 40 mph (64.37 km/h) | 39.92 mph (64.24 km/h) |
| 45 mph (72.42 km/h) | 44.91 mph (72.27 km/h) |
| 50 mph (80.47 km/h) | 49.9 mph (80.3 km/h) |
| 55 mph (88.51 km/h) | 54.89 mph (88.33 km/h) |
| 60 mph (96.56 km/h) | 59.88 mph (96.36 km/h) |
| 65 mph (104.61 km/h) | 64.87 mph (104.39 km/h) |
| 70 mph (112.65 km/h) | 69.86 mph (112.43 km/h) |
| 75 mph (120.7 km/h) | 74.85 mph (120.46 km/h) |
| 80 mph (128.75 km/h) | 79.84 mph (128.49 km/h) |
| 85 mph (136.79 km/h) | 84.83 mph (136.52 km/h) |
| 90 mph (144.84 km/h) | 89.82 mph (144.55 km/h) |
| 95 mph (152.89 km/h) | 94.81 mph (152.58 km/h) |
| 100 mph (160.93 km/h) | 99.8 mph (160.61 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1771 | 2058 | 2216 | 2314 | 2419 | 2495 | 2578 | 2676 | 2811 | 2947 | 3098 | 3218 | 3437 | 3678 | 3867 | 3987 | 4055 | 4304 | 4650 | 5404 |
Better Fuel Economy Factory Ratios Increased Power
