Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 305/40-20 | 315/40-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 29.61 (752) | 29.92 (760) | 0.31 (8) 1.1% |
| Width inches (mm) | 12.01 (305) | 12.4 (315) | 0.39 (10) 3.3% |
| Circum. inches (mm) | 93.01 (2362.48) | 94 (2387.61) | 0.99 (25.13) 1.1% |
| Sidewall Height inches (mm) | 4.8 (122) | 4.96 (126) | 0.16 (4) 3.3% |
| Revolutions per mile (km) | 681.21 (423.28) | 674.04 (418.83) | -7.17 (-4.46) -1.1% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.21 mph (32.53 km/h) |
| 25 mph (40.23 km/h) | 25.27 mph (40.66 km/h) |
| 30 mph (48.28 km/h) | 30.32 mph (48.79 km/h) |
| 35 mph (56.33 km/h) | 35.37 mph (56.93 km/h) |
| 40 mph (64.37 km/h) | 40.43 mph (65.06 km/h) |
| 45 mph (72.42 km/h) | 45.48 mph (73.19 km/h) |
| 50 mph (80.47 km/h) | 50.53 mph (81.32 km/h) |
| 55 mph (88.51 km/h) | 55.59 mph (89.46 km/h) |
| 60 mph (96.56 km/h) | 60.64 mph (97.59 km/h) |
| 65 mph (104.61 km/h) | 65.69 mph (105.72 km/h) |
| 70 mph (112.65 km/h) | 70.74 mph (113.85 km/h) |
| 75 mph (120.7 km/h) | 75.8 mph (121.99 km/h) |
| 80 mph (128.75 km/h) | 80.85 mph (130.12 km/h) |
| 85 mph (136.79 km/h) | 85.9 mph (138.25 km/h) |
| 90 mph (144.84 km/h) | 90.96 mph (146.38 km/h) |
| 95 mph (152.89 km/h) | 96.01 mph (154.51 km/h) |
| 100 mph (160.93 km/h) | 101.06 mph (162.65 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
