Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/25-21 | 425/75-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.4 (695.9) | 45.1 (1145.5) | 17.7 (449.6) 64.6% |
| Width inches (mm) | 12.8 (325) | 16.73 (425) | 3.94 (100) 30.8% |
| Circum. inches (mm) | 86.07 (2186.23) | 141.68 (3598.69) | 55.61 (1412.46) 64.6% |
| Sidewall Height inches (mm) | 3.2 (81.25) | 12.55 (318.75) | 9.35 (237.5) 292.3% |
| Revolutions per mile (km) | 736.13 (457.41) | 447.2 (277.88) | -288.92 (-179.53) -39.2% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 32.92 mph (52.98 km/h) |
| 25 mph (40.23 km/h) | 41.15 mph (66.23 km/h) |
| 30 mph (48.28 km/h) | 49.38 mph (79.47 km/h) |
| 35 mph (56.33 km/h) | 57.61 mph (92.72 km/h) |
| 40 mph (64.37 km/h) | 65.84 mph (105.96 km/h) |
| 45 mph (72.42 km/h) | 74.07 mph (119.21 km/h) |
| 50 mph (80.47 km/h) | 82.3 mph (132.45 km/h) |
| 55 mph (88.51 km/h) | 90.53 mph (145.7 km/h) |
| 60 mph (96.56 km/h) | 98.76 mph (158.95 km/h) |
| 65 mph (104.61 km/h) | 106.99 mph (172.19 km/h) |
| 70 mph (112.65 km/h) | 115.22 mph (185.44 km/h) |
| 75 mph (120.7 km/h) | 123.46 mph (198.68 km/h) |
| 80 mph (128.75 km/h) | 131.69 mph (211.93 km/h) |
| 85 mph (136.79 km/h) | 139.92 mph (225.17 km/h) |
| 90 mph (144.84 km/h) | 148.15 mph (238.42 km/h) |
| 95 mph (152.89 km/h) | 156.38 mph (251.66 km/h) |
| 100 mph (160.93 km/h) | 164.61 mph (264.91 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
