Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/25-21 | 325/20-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.4 (695.9) | 26.12 (663.4) | -1.28 (-32.5) -4.7% |
| Width inches (mm) | 12.8 (325) | 12.8 (325) | 0 (0) 0% |
| Circum. inches (mm) | 86.07 (2186.23) | 82.05 (2084.13) | -4.02 (-102.1) -4.7% |
| Sidewall Height inches (mm) | 3.2 (81.25) | 2.56 (65) | -0.64 (-16.25) -20% |
| Revolutions per mile (km) | 736.13 (457.41) | 772.19 (479.82) | 36.06 (22.41) 4.9% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.07 mph (30.68 km/h) |
| 25 mph (40.23 km/h) | 23.83 mph (38.35 km/h) |
| 30 mph (48.28 km/h) | 28.6 mph (46.03 km/h) |
| 35 mph (56.33 km/h) | 33.37 mph (53.7 km/h) |
| 40 mph (64.37 km/h) | 38.13 mph (61.37 km/h) |
| 45 mph (72.42 km/h) | 42.9 mph (69.04 km/h) |
| 50 mph (80.47 km/h) | 47.66 mph (76.71 km/h) |
| 55 mph (88.51 km/h) | 52.43 mph (84.38 km/h) |
| 60 mph (96.56 km/h) | 57.2 mph (92.05 km/h) |
| 65 mph (104.61 km/h) | 61.96 mph (99.72 km/h) |
| 70 mph (112.65 km/h) | 66.73 mph (107.39 km/h) |
| 75 mph (120.7 km/h) | 71.5 mph (115.06 km/h) |
| 80 mph (128.75 km/h) | 76.26 mph (122.73 km/h) |
| 85 mph (136.79 km/h) | 81.03 mph (130.41 km/h) |
| 90 mph (144.84 km/h) | 85.8 mph (138.08 km/h) |
| 95 mph (152.89 km/h) | 90.56 mph (145.75 km/h) |
| 100 mph (160.93 km/h) | 95.33 mph (153.42 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1965 | 2283 | 2458 | 2567 | 2684 | 2768 | 2860 | 2969 | 3119 | 3270 | 3437 | 3571 | 3813 | 4081 | 4290 | 4424 | 4499 | 4775 | 5159 | 5996 |
Better Fuel Economy Factory Ratios Increased Power
