Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 305/45-20 | 315/40-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 30.81 (782.5) | 29.92 (760) | -0.89 (-22.5) -2.9% |
| Width inches (mm) | 12.01 (305) | 12.4 (315) | 0.39 (10) 3.3% |
| Circum. inches (mm) | 96.78 (2458.3) | 94 (2387.61) | -2.78 (-70.69) -2.9% |
| Sidewall Height inches (mm) | 5.4 (137.25) | 4.96 (126) | -0.44 (-11.25) -8.2% |
| Revolutions per mile (km) | 654.66 (406.79) | 674.04 (418.83) | 19.38 (12.04) 3% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.42 mph (31.26 km/h) |
| 25 mph (40.23 km/h) | 24.28 mph (39.08 km/h) |
| 30 mph (48.28 km/h) | 29.14 mph (46.89 km/h) |
| 35 mph (56.33 km/h) | 33.99 mph (54.71 km/h) |
| 40 mph (64.37 km/h) | 38.85 mph (62.52 km/h) |
| 45 mph (72.42 km/h) | 43.71 mph (70.34 km/h) |
| 50 mph (80.47 km/h) | 48.56 mph (78.15 km/h) |
| 55 mph (88.51 km/h) | 53.42 mph (85.97 km/h) |
| 60 mph (96.56 km/h) | 58.27 mph (93.78 km/h) |
| 65 mph (104.61 km/h) | 63.13 mph (101.6 km/h) |
| 70 mph (112.65 km/h) | 67.99 mph (109.42 km/h) |
| 75 mph (120.7 km/h) | 72.84 mph (117.23 km/h) |
| 80 mph (128.75 km/h) | 77.7 mph (125.05 km/h) |
| 85 mph (136.79 km/h) | 82.56 mph (132.86 km/h) |
| 90 mph (144.84 km/h) | 87.41 mph (140.68 km/h) |
| 95 mph (152.89 km/h) | 92.27 mph (148.49 km/h) |
| 100 mph (160.93 km/h) | 97.12 mph (156.31 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1715 | 1993 | 2146 | 2241 | 2343 | 2416 | 2496 | 2591 | 2723 | 2854 | 3000 | 3117 | 3328 | 3562 | 3744 | 3861 | 3927 | 4168 | 4504 | 5233 |
Better Fuel Economy Factory Ratios Increased Power
