Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 180/70-18 | 320/65-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.92 (709.2) | 34.38 (873.2) | 6.46 (164) 23.1% |
| Width inches (mm) | 7.09 (180) | 12.6 (320) | 5.51 (140) 77.8% |
| Circum. inches (mm) | 87.72 (2228.02) | 108 (2743.24) | 20.28 (515.22) 23.1% |
| Sidewall Height inches (mm) | 4.96 (126) | 8.19 (208) | 3.23 (82) 65.1% |
| Revolutions per mile (km) | 722.32 (448.83) | 586.66 (364.53) | -135.66 (-84.3) -18.8% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 24.62 mph (39.63 km/h) |
| 25 mph (40.23 km/h) | 30.78 mph (49.54 km/h) |
| 30 mph (48.28 km/h) | 36.94 mph (59.45 km/h) |
| 35 mph (56.33 km/h) | 43.09 mph (69.35 km/h) |
| 40 mph (64.37 km/h) | 49.25 mph (79.26 km/h) |
| 45 mph (72.42 km/h) | 55.41 mph (89.17 km/h) |
| 50 mph (80.47 km/h) | 61.56 mph (99.08 km/h) |
| 55 mph (88.51 km/h) | 67.72 mph (108.98 km/h) |
| 60 mph (96.56 km/h) | 73.87 mph (118.89 km/h) |
| 65 mph (104.61 km/h) | 80.03 mph (128.8 km/h) |
| 70 mph (112.65 km/h) | 86.19 mph (138.71 km/h) |
| 75 mph (120.7 km/h) | 92.34 mph (148.61 km/h) |
| 80 mph (128.75 km/h) | 98.5 mph (158.52 km/h) |
| 85 mph (136.79 km/h) | 104.66 mph (168.43 km/h) |
| 90 mph (144.84 km/h) | 110.81 mph (178.34 km/h) |
| 95 mph (152.89 km/h) | 116.97 mph (188.24 km/h) |
| 100 mph (160.93 km/h) | 123.12 mph (198.15 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1493 | 1734 | 1868 | 1950 | 2039 | 2103 | 2173 | 2255 | 2370 | 2484 | 2611 | 2713 | 2897 | 3100 | 3259 | 3361 | 3418 | 3628 | 3920 | 4555 |
Better Fuel Economy Factory Ratios Increased Power
