Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 285/40-18 | 305/40-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 26.98 (685.2) | 27.61 (701.2) | 0.63 (16) 2.3% |
| Width inches (mm) | 11.22 (285) | 12.01 (305) | 0.79 (20) 7% |
| Circum. inches (mm) | 84.75 (2152.62) | 86.73 (2202.88) | 1.98 (50.27) 2.3% |
| Sidewall Height inches (mm) | 4.49 (114) | 4.8 (122) | 0.31 (8) 7% |
| Revolutions per mile (km) | 747.62 (464.55) | 730.56 (453.95) | -17.06 (-10.6) -2.3% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.47 mph (32.94 km/h) |
| 25 mph (40.23 km/h) | 25.58 mph (41.17 km/h) |
| 30 mph (48.28 km/h) | 30.7 mph (49.41 km/h) |
| 35 mph (56.33 km/h) | 35.82 mph (57.64 km/h) |
| 40 mph (64.37 km/h) | 40.93 mph (65.88 km/h) |
| 45 mph (72.42 km/h) | 46.05 mph (74.11 km/h) |
| 50 mph (80.47 km/h) | 51.17 mph (82.35 km/h) |
| 55 mph (88.51 km/h) | 56.28 mph (90.58 km/h) |
| 60 mph (96.56 km/h) | 61.4 mph (98.82 km/h) |
| 65 mph (104.61 km/h) | 66.52 mph (107.05 km/h) |
| 70 mph (112.65 km/h) | 71.63 mph (115.28 km/h) |
| 75 mph (120.7 km/h) | 76.75 mph (123.52 km/h) |
| 80 mph (128.75 km/h) | 81.87 mph (131.75 km/h) |
| 85 mph (136.79 km/h) | 86.98 mph (139.99 km/h) |
| 90 mph (144.84 km/h) | 92.1 mph (148.22 km/h) |
| 95 mph (152.89 km/h) | 97.22 mph (156.46 km/h) |
| 100 mph (160.93 km/h) | 102.34 mph (164.69 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1859 | 2160 | 2326 | 2429 | 2540 | 2619 | 2706 | 2808 | 2951 | 3093 | 3252 | 3378 | 3608 | 3861 | 4058 | 4185 | 4256 | 4517 | 4881 | 5672 |
Better Fuel Economy Factory Ratios Increased Power
