Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 40/12.5-20 | 320/90-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 40.03 (1016.8) | 42.68 (1084) | 2.65 (67.2) 6.6% |
| Width inches (mm) | 12.52 (318) | 12.6 (320) | 0.08 (2) 0.6% |
| Circum. inches (mm) | 125.76 (3194.37) | 134.07 (3405.49) | 8.31 (211.12) 6.6% |
| Sidewall Height inches (mm) | 10.02 (254.4) | 11.34 (288) | 1.32 (33.6) 13.2% |
| Revolutions per mile (km) | 503.81 (313.05) | 472.57 (293.64) | -31.23 (-19.41) -6.2% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.32 mph (34.31 km/h) |
| 25 mph (40.23 km/h) | 26.65 mph (42.89 km/h) |
| 30 mph (48.28 km/h) | 31.98 mph (51.47 km/h) |
| 35 mph (56.33 km/h) | 37.31 mph (60.05 km/h) |
| 40 mph (64.37 km/h) | 42.64 mph (68.63 km/h) |
| 45 mph (72.42 km/h) | 47.97 mph (77.21 km/h) |
| 50 mph (80.47 km/h) | 53.3 mph (85.79 km/h) |
| 55 mph (88.51 km/h) | 58.63 mph (94.36 km/h) |
| 60 mph (96.56 km/h) | 63.97 mph (102.94 km/h) |
| 65 mph (104.61 km/h) | 69.3 mph (111.52 km/h) |
| 70 mph (112.65 km/h) | 74.63 mph (120.1 km/h) |
| 75 mph (120.7 km/h) | 79.96 mph (128.68 km/h) |
| 80 mph (128.75 km/h) | 85.29 mph (137.26 km/h) |
| 85 mph (136.79 km/h) | 90.62 mph (145.84 km/h) |
| 90 mph (144.84 km/h) | 95.95 mph (154.41 km/h) |
| 95 mph (152.89 km/h) | 101.28 mph (162.99 km/h) |
| 100 mph (160.93 km/h) | 106.61 mph (171.57 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1203 | 1397 | 1505 | 1571 | 1643 | 1694 | 1750 | 1817 | 1909 | 2001 | 2103 | 2185 | 2334 | 2497 | 2625 | 2707 | 2753 | 2922 | 3157 | 3669 |
Better Fuel Economy Factory Ratios Increased Power
