Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 305/45-20 | 31/10.5-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 30.81 (782.5) | 30.93 (785.68) | 0.13 (3.18) 0.4% |
| Width inches (mm) | 12.01 (305) | 10.51 (267) | -1.5 (-38) -12.5% |
| Circum. inches (mm) | 96.78 (2458.3) | 97.18 (2468.29) | 0.39 (9.99) 0.4% |
| Sidewall Height inches (mm) | 5.4 (137.25) | 5.47 (138.84) | 0.06 (1.59) 1.2% |
| Revolutions per mile (km) | 654.66 (406.79) | 652.01 (405.14) | -2.65 (-1.65) -0.4% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.08 mph (32.32 km/h) |
| 25 mph (40.23 km/h) | 25.1 mph (40.4 km/h) |
| 30 mph (48.28 km/h) | 30.12 mph (48.48 km/h) |
| 35 mph (56.33 km/h) | 35.14 mph (56.56 km/h) |
| 40 mph (64.37 km/h) | 40.16 mph (64.64 km/h) |
| 45 mph (72.42 km/h) | 45.18 mph (72.71 km/h) |
| 50 mph (80.47 km/h) | 50.2 mph (80.79 km/h) |
| 55 mph (88.51 km/h) | 55.22 mph (88.87 km/h) |
| 60 mph (96.56 km/h) | 60.24 mph (96.95 km/h) |
| 65 mph (104.61 km/h) | 65.26 mph (105.03 km/h) |
| 70 mph (112.65 km/h) | 70.28 mph (113.11 km/h) |
| 75 mph (120.7 km/h) | 75.3 mph (121.19 km/h) |
| 80 mph (128.75 km/h) | 80.33 mph (129.27 km/h) |
| 85 mph (136.79 km/h) | 85.35 mph (137.35 km/h) |
| 90 mph (144.84 km/h) | 90.37 mph (145.43 km/h) |
| 95 mph (152.89 km/h) | 95.39 mph (153.51 km/h) |
| 100 mph (160.93 km/h) | 100.41 mph (161.59 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1659 | 1928 | 2076 | 2168 | 2266 | 2337 | 2415 | 2507 | 2634 | 2761 | 2902 | 3015 | 3220 | 3446 | 3622 | 3735 | 3799 | 4032 | 4356 | 5062 |
Better Fuel Economy Factory Ratios Increased Power
