Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/25-21 | 325/30-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.4 (695.9) | 28.68 (728.4) | 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) | 90.09 (2288.34) | 4.02 (102.1) 4.7% |
| Sidewall Height inches (mm) | 3.2 (81.25) | 3.84 (97.5) | 0.64 (16.25) 20% |
| Revolutions per mile (km) | 736.13 (457.41) | 703.28 (437) | -32.84 (-20.41) -4.5% |
325/30-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.93 mph (33.69 km/h) |
| 25 mph (40.23 km/h) | 26.17 mph (42.11 km/h) |
| 30 mph (48.28 km/h) | 31.4 mph (50.54 km/h) |
| 35 mph (56.33 km/h) | 36.63 mph (58.96 km/h) |
| 40 mph (64.37 km/h) | 41.87 mph (67.38 km/h) |
| 45 mph (72.42 km/h) | 47.1 mph (75.8 km/h) |
| 50 mph (80.47 km/h) | 52.34 mph (84.23 km/h) |
| 55 mph (88.51 km/h) | 57.57 mph (92.65 km/h) |
| 60 mph (96.56 km/h) | 62.8 mph (101.07 km/h) |
| 65 mph (104.61 km/h) | 68.04 mph (109.49 km/h) |
| 70 mph (112.65 km/h) | 73.27 mph (117.92 km/h) |
| 75 mph (120.7 km/h) | 78.5 mph (126.34 km/h) |
| 80 mph (128.75 km/h) | 83.74 mph (134.76 km/h) |
| 85 mph (136.79 km/h) | 88.97 mph (143.18 km/h) |
| 90 mph (144.84 km/h) | 94.2 mph (151.61 km/h) |
| 95 mph (152.89 km/h) | 99.44 mph (160.03 km/h) |
| 100 mph (160.93 km/h) | 104.67 mph (168.45 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1790 | 2079 | 2239 | 2338 | 2445 | 2521 | 2605 | 2704 | 2841 | 2978 | 3130 | 3252 | 3473 | 3717 | 3907 | 4029 | 4097 | 4349 | 4699 | 5461 |
Better Fuel Economy Factory Ratios Increased Power
