Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 315/30-18 | 315/40-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 25.44 (646.2) | 27.92 (709.2) | 2.48 (63) 9.7% |
| Width inches (mm) | 12.4 (315) | 12.4 (315) | 0 (0) 0% |
| Circum. inches (mm) | 79.93 (2030.1) | 87.72 (2228.02) | 7.79 (197.92) 9.7% |
| Sidewall Height inches (mm) | 3.72 (94.5) | 4.96 (126) | 1.24 (31.5) 33.3% |
| Revolutions per mile (km) | 792.74 (492.59) | 722.32 (448.83) | -70.42 (-43.76) -8.9% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.95 mph (35.32 km/h) |
| 25 mph (40.23 km/h) | 27.44 mph (44.16 km/h) |
| 30 mph (48.28 km/h) | 32.92 mph (52.99 km/h) |
| 35 mph (56.33 km/h) | 38.41 mph (61.82 km/h) |
| 40 mph (64.37 km/h) | 43.9 mph (70.65 km/h) |
| 45 mph (72.42 km/h) | 49.39 mph (79.48 km/h) |
| 50 mph (80.47 km/h) | 54.87 mph (88.31 km/h) |
| 55 mph (88.51 km/h) | 60.36 mph (97.14 km/h) |
| 60 mph (96.56 km/h) | 65.85 mph (105.97 km/h) |
| 65 mph (104.61 km/h) | 71.34 mph (114.81 km/h) |
| 70 mph (112.65 km/h) | 76.82 mph (123.64 km/h) |
| 75 mph (120.7 km/h) | 82.31 mph (132.47 km/h) |
| 80 mph (128.75 km/h) | 87.8 mph (141.3 km/h) |
| 85 mph (136.79 km/h) | 93.29 mph (150.13 km/h) |
| 90 mph (144.84 km/h) | 98.77 mph (158.96 km/h) |
| 95 mph (152.89 km/h) | 104.26 mph (167.79 km/h) |
| 100 mph (160.93 km/h) | 109.75 mph (176.62 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1838 | 2135 | 2300 | 2401 | 2511 | 2589 | 2675 | 2777 | 2918 | 3058 | 3215 | 3340 | 3567 | 3817 | 4013 | 4138 | 4208 | 4466 | 4826 | 5608 |
Better Fuel Economy Factory Ratios Increased Power
