Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/25-21 | 345/30-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.4 (695.9) | 26.15 (664.2) | -1.25 (-31.7) -4.6% |
| Width inches (mm) | 12.8 (325) | 13.58 (345) | 0.79 (20) 6.2% |
| Circum. inches (mm) | 86.07 (2186.23) | 82.15 (2086.65) | -3.92 (-99.59) -4.6% |
| Sidewall Height inches (mm) | 3.2 (81.25) | 4.07 (103.5) | 0.88 (22.25) 27.4% |
| Revolutions per mile (km) | 736.13 (457.41) | 771.26 (479.24) | 35.13 (21.83) 4.8% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.09 mph (30.72 km/h) |
| 25 mph (40.23 km/h) | 23.86 mph (38.4 km/h) |
| 30 mph (48.28 km/h) | 28.63 mph (46.08 km/h) |
| 35 mph (56.33 km/h) | 33.41 mph (53.76 km/h) |
| 40 mph (64.37 km/h) | 38.18 mph (61.44 km/h) |
| 45 mph (72.42 km/h) | 42.95 mph (69.12 km/h) |
| 50 mph (80.47 km/h) | 47.72 mph (76.8 km/h) |
| 55 mph (88.51 km/h) | 52.49 mph (84.48 km/h) |
| 60 mph (96.56 km/h) | 57.27 mph (92.16 km/h) |
| 65 mph (104.61 km/h) | 62.04 mph (99.84 km/h) |
| 70 mph (112.65 km/h) | 66.81 mph (107.52 km/h) |
| 75 mph (120.7 km/h) | 71.58 mph (115.2 km/h) |
| 80 mph (128.75 km/h) | 76.36 mph (122.88 km/h) |
| 85 mph (136.79 km/h) | 81.13 mph (130.56 km/h) |
| 90 mph (144.84 km/h) | 85.9 mph (138.24 km/h) |
| 95 mph (152.89 km/h) | 90.67 mph (145.92 km/h) |
| 100 mph (160.93 km/h) | 95.44 mph (153.6 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1963 | 2280 | 2455 | 2564 | 2681 | 2764 | 2856 | 2965 | 3115 | 3266 | 3433 | 3566 | 3808 | 4076 | 4285 | 4418 | 4493 | 4769 | 5153 | 5988 |
Better Fuel Economy Factory Ratios Increased Power
