Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/30-21 | 275/45-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.68 (728.4) | 30.74 (780.9) | 2.07 (52.5) 7.2% |
| Width inches (mm) | 12.8 (325) | 10.83 (275) | -1.97 (-50) -15.4% |
| Circum. inches (mm) | 90.09 (2288.34) | 96.59 (2453.27) | 6.49 (164.93) 7.2% |
| Sidewall Height inches (mm) | 3.84 (97.5) | 4.87 (123.75) | 1.03 (26.25) 26.9% |
| Revolutions per mile (km) | 703.28 (437) | 656 (407.62) | -47.28 (-29.38) -6.7% |
275/45-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.44 mph (34.51 km/h) |
| 25 mph (40.23 km/h) | 26.8 mph (43.13 km/h) |
| 30 mph (48.28 km/h) | 32.16 mph (51.76 km/h) |
| 35 mph (56.33 km/h) | 37.52 mph (60.39 km/h) |
| 40 mph (64.37 km/h) | 42.88 mph (69.01 km/h) |
| 45 mph (72.42 km/h) | 48.24 mph (77.64 km/h) |
| 50 mph (80.47 km/h) | 53.6 mph (86.27 km/h) |
| 55 mph (88.51 km/h) | 58.96 mph (94.89 km/h) |
| 60 mph (96.56 km/h) | 64.32 mph (103.52 km/h) |
| 65 mph (104.61 km/h) | 69.68 mph (112.15 km/h) |
| 70 mph (112.65 km/h) | 75.05 mph (120.77 km/h) |
| 75 mph (120.7 km/h) | 80.41 mph (129.4 km/h) |
| 80 mph (128.75 km/h) | 85.77 mph (138.03 km/h) |
| 85 mph (136.79 km/h) | 91.13 mph (146.65 km/h) |
| 90 mph (144.84 km/h) | 96.49 mph (155.28 km/h) |
| 95 mph (152.89 km/h) | 101.85 mph (163.91 km/h) |
| 100 mph (160.93 km/h) | 107.21 mph (172.53 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1669 | 1939 | 2089 | 2181 | 2280 | 2351 | 2430 | 2522 | 2650 | 2778 | 2920 | 3033 | 3239 | 3467 | 3644 | 3758 | 3822 | 4056 | 4383 | 5093 |
Better Fuel Economy Factory Ratios Increased Power
