Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 315/60-20 | 305/60-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 34.88 (886) | 32.41 (823.2) | -2.47 (-62.8) -7.1% |
| Width inches (mm) | 12.4 (315) | 12.01 (305) | -0.39 (-10) -3.2% |
| Circum. inches (mm) | 109.58 (2783.45) | 101.82 (2586.16) | -7.77 (-197.29) -7.1% |
| Sidewall Height inches (mm) | 7.44 (189) | 7.2 (183) | -0.24 (-6) -3.2% |
| Revolutions per mile (km) | 578.18 (359.27) | 622.29 (386.67) | 44.11 (27.41) 7.6% |
305/60-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.58 mph (29.91 km/h) |
| 25 mph (40.23 km/h) | 23.23 mph (37.38 km/h) |
| 30 mph (48.28 km/h) | 27.87 mph (44.86 km/h) |
| 35 mph (56.33 km/h) | 32.52 mph (52.33 km/h) |
| 40 mph (64.37 km/h) | 37.16 mph (59.81 km/h) |
| 45 mph (72.42 km/h) | 41.81 mph (67.29 km/h) |
| 50 mph (80.47 km/h) | 46.46 mph (74.76 km/h) |
| 55 mph (88.51 km/h) | 51.1 mph (82.24 km/h) |
| 60 mph (96.56 km/h) | 55.75 mph (89.72 km/h) |
| 65 mph (104.61 km/h) | 60.39 mph (97.19 km/h) |
| 70 mph (112.65 km/h) | 65.04 mph (104.67 km/h) |
| 75 mph (120.7 km/h) | 69.68 mph (112.15 km/h) |
| 80 mph (128.75 km/h) | 74.33 mph (119.62 km/h) |
| 85 mph (136.79 km/h) | 78.98 mph (127.1 km/h) |
| 90 mph (144.84 km/h) | 83.62 mph (134.57 km/h) |
| 95 mph (152.89 km/h) | 88.27 mph (142.05 km/h) |
| 100 mph (160.93 km/h) | 92.91 mph (149.53 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1584 | 1840 | 1981 | 2069 | 2163 | 2231 | 2305 | 2392 | 2514 | 2635 | 2770 | 2877 | 3073 | 3289 | 3457 | 3565 | 3625 | 3848 | 4158 | 4832 |
Better Fuel Economy Factory Ratios Increased Power
