Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 38/15.5-20 | 40/14.5-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 37.99 (965.04) | 39.99 (1015.84) | 2 (50.8) 5.3% |
| Width inches (mm) | 15.51 (394) | 14.49 (368) | -1.02 (-26) -6.6% |
| Circum. inches (mm) | 119.36 (3031.76) | 125.64 (3191.36) | 6.28 (159.59) 5.3% |
| Sidewall Height inches (mm) | 9 (228.52) | 10 (253.92) | 1 (25.4) 11.1% |
| Revolutions per mile (km) | 530.83 (329.84) | 504.28 (313.35) | -26.55 (-16.49) -5% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.05 mph (33.88 km/h) |
| 25 mph (40.23 km/h) | 26.32 mph (42.35 km/h) |
| 30 mph (48.28 km/h) | 31.58 mph (50.82 km/h) |
| 35 mph (56.33 km/h) | 36.84 mph (59.29 km/h) |
| 40 mph (64.37 km/h) | 42.11 mph (67.76 km/h) |
| 45 mph (72.42 km/h) | 47.37 mph (76.23 km/h) |
| 50 mph (80.47 km/h) | 52.63 mph (84.7 km/h) |
| 55 mph (88.51 km/h) | 57.9 mph (93.17 km/h) |
| 60 mph (96.56 km/h) | 63.16 mph (101.64 km/h) |
| 65 mph (104.61 km/h) | 68.42 mph (110.11 km/h) |
| 70 mph (112.65 km/h) | 73.68 mph (118.58 km/h) |
| 75 mph (120.7 km/h) | 78.95 mph (127.05 km/h) |
| 80 mph (128.75 km/h) | 84.21 mph (135.53 km/h) |
| 85 mph (136.79 km/h) | 89.47 mph (144 km/h) |
| 90 mph (144.84 km/h) | 94.74 mph (152.47 km/h) |
| 95 mph (152.89 km/h) | 100 mph (160.94 km/h) |
| 100 mph (160.93 km/h) | 105.26 mph (169.41 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1283 | 1491 | 1605 | 1676 | 1753 | 1808 | 1868 | 1939 | 2037 | 2135 | 2244 | 2332 | 2490 | 2665 | 2801 | 2889 | 2938 | 3118 | 3369 | 3915 |
Better Fuel Economy Factory Ratios Increased Power
