Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 180/70-18 | 420/85-30 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.92 (709.2) | 58.11 (1476) | 30.19 (766.8) 108.1% |
| Width inches (mm) | 7.09 (180) | 16.54 (420) | 9.45 (240) 133.3% |
| Circum. inches (mm) | 87.72 (2228.02) | 182.56 (4636.99) | 94.84 (2408.97) 108.1% |
| Sidewall Height inches (mm) | 4.96 (126) | 14.06 (357) | 9.09 (231) 183.3% |
| Revolutions per mile (km) | 722.32 (448.83) | 347.07 (215.66) | -375.25 (-233.17) -52% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 41.62 mph (66.99 km/h) |
| 25 mph (40.23 km/h) | 52.03 mph (83.74 km/h) |
| 30 mph (48.28 km/h) | 62.44 mph (100.48 km/h) |
| 35 mph (56.33 km/h) | 72.84 mph (117.23 km/h) |
| 40 mph (64.37 km/h) | 83.25 mph (133.98 km/h) |
| 45 mph (72.42 km/h) | 93.65 mph (150.72 km/h) |
| 50 mph (80.47 km/h) | 104.06 mph (167.47 km/h) |
| 55 mph (88.51 km/h) | 114.47 mph (184.22 km/h) |
| 60 mph (96.56 km/h) | 124.87 mph (200.96 km/h) |
| 65 mph (104.61 km/h) | 135.28 mph (217.71 km/h) |
| 70 mph (112.65 km/h) | 145.69 mph (234.46 km/h) |
| 75 mph (120.7 km/h) | 156.09 mph (251.21 km/h) |
| 80 mph (128.75 km/h) | 166.5 mph (267.95 km/h) |
| 85 mph (136.79 km/h) | 176.9 mph (284.7 km/h) |
| 90 mph (144.84 km/h) | 187.31 mph (301.45 km/h) |
| 95 mph (152.89 km/h) | 197.72 mph (318.19 km/h) |
| 100 mph (160.93 km/h) | 208.12 mph (334.94 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Better Fuel Economy Factory Ratios Increased Power
