Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 175/90-18 | 405/85-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 30.4 (772.2) | 47.11 (1196.5) | 16.7 (424.3) 54.9% |
| Width inches (mm) | 6.89 (175) | 15.94 (405) | 9.06 (230) 131.4% |
| Circum. inches (mm) | 95.51 (2425.94) | 147.99 (3758.92) | 52.48 (1332.98) 54.9% |
| Sidewall Height inches (mm) | 6.2 (157.5) | 13.55 (344.25) | 7.35 (186.75) 118.6% |
| Revolutions per mile (km) | 663.39 (412.21) | 428.14 (266.03) | -235.25 (-146.18) -35.5% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 30.99 mph (49.87 km/h) |
| 25 mph (40.23 km/h) | 38.74 mph (62.34 km/h) |
| 30 mph (48.28 km/h) | 46.48 mph (74.81 km/h) |
| 35 mph (56.33 km/h) | 54.23 mph (87.28 km/h) |
| 40 mph (64.37 km/h) | 61.98 mph (99.75 km/h) |
| 45 mph (72.42 km/h) | 69.73 mph (112.21 km/h) |
| 50 mph (80.47 km/h) | 77.47 mph (124.68 km/h) |
| 55 mph (88.51 km/h) | 85.22 mph (137.15 km/h) |
| 60 mph (96.56 km/h) | 92.97 mph (149.62 km/h) |
| 65 mph (104.61 km/h) | 100.72 mph (162.09 km/h) |
| 70 mph (112.65 km/h) | 108.46 mph (174.55 km/h) |
| 75 mph (120.7 km/h) | 116.21 mph (187.02 km/h) |
| 80 mph (128.75 km/h) | 123.96 mph (199.49 km/h) |
| 85 mph (136.79 km/h) | 131.7 mph (211.96 km/h) |
| 90 mph (144.84 km/h) | 139.45 mph (224.43 km/h) |
| 95 mph (152.89 km/h) | 147.2 mph (236.9 km/h) |
| 100 mph (160.93 km/h) | 154.95 mph (249.36 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
