Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/30-20 | 30/12-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.68 (703) | 30.09 (764.2) | 2.41 (61.2) 8.7% |
| Width inches (mm) | 12.8 (325) | 12.01 (305) | -0.79 (-20) -6.2% |
| Circum. inches (mm) | 86.95 (2208.54) | 94.52 (2400.81) | 7.57 (192.27) 8.7% |
| Sidewall Height inches (mm) | 3.84 (97.5) | 5.04 (128.1) | 1.2 (30.6) 31.4% |
| Revolutions per mile (km) | 728.69 (452.79) | 670.34 (416.53) | -58.36 (-36.26) -8% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.74 mph (34.99 km/h) |
| 25 mph (40.23 km/h) | 27.18 mph (43.74 km/h) |
| 30 mph (48.28 km/h) | 32.61 mph (52.48 km/h) |
| 35 mph (56.33 km/h) | 38.05 mph (61.23 km/h) |
| 40 mph (64.37 km/h) | 43.48 mph (69.98 km/h) |
| 45 mph (72.42 km/h) | 48.92 mph (78.73 km/h) |
| 50 mph (80.47 km/h) | 54.35 mph (87.47 km/h) |
| 55 mph (88.51 km/h) | 59.79 mph (96.22 km/h) |
| 60 mph (96.56 km/h) | 65.22 mph (104.97 km/h) |
| 65 mph (104.61 km/h) | 70.66 mph (113.71 km/h) |
| 70 mph (112.65 km/h) | 76.09 mph (122.46 km/h) |
| 75 mph (120.7 km/h) | 81.53 mph (131.21 km/h) |
| 80 mph (128.75 km/h) | 86.96 mph (139.96 km/h) |
| 85 mph (136.79 km/h) | 92.4 mph (148.7 km/h) |
| 90 mph (144.84 km/h) | 97.83 mph (157.45 km/h) |
| 95 mph (152.89 km/h) | 103.27 mph (166.2 km/h) |
| 100 mph (160.93 km/h) | 108.71 mph (174.94 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1706 | 1982 | 2134 | 2229 | 2330 | 2403 | 2483 | 2577 | 2708 | 2838 | 2983 | 3100 | 3310 | 3542 | 3724 | 3840 | 3905 | 4145 | 4479 | 5205 |
Better Fuel Economy Factory Ratios Increased Power
