Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/40-18 | 325/55-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.24 (717.2) | 32.07 (814.7) | 3.84 (97.5) 13.6% |
| Width inches (mm) | 12.8 (325) | 12.8 (325) | 0 (0) 0% |
| Circum. inches (mm) | 88.71 (2253.15) | 100.77 (2559.46) | 12.06 (306.31) 13.6% |
| Sidewall Height inches (mm) | 5.12 (130) | 7.04 (178.75) | 1.92 (48.75) 37.5% |
| Revolutions per mile (km) | 714.26 (443.82) | 628.78 (390.71) | -85.48 (-53.11) -12% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 22.72 mph (36.56 km/h) |
| 25 mph (40.23 km/h) | 28.4 mph (45.7 km/h) |
| 30 mph (48.28 km/h) | 34.08 mph (54.84 km/h) |
| 35 mph (56.33 km/h) | 39.76 mph (63.98 km/h) |
| 40 mph (64.37 km/h) | 45.44 mph (73.13 km/h) |
| 45 mph (72.42 km/h) | 51.12 mph (82.27 km/h) |
| 50 mph (80.47 km/h) | 56.8 mph (91.41 km/h) |
| 55 mph (88.51 km/h) | 62.48 mph (100.55 km/h) |
| 60 mph (96.56 km/h) | 68.16 mph (109.69 km/h) |
| 65 mph (104.61 km/h) | 73.84 mph (118.83 km/h) |
| 70 mph (112.65 km/h) | 79.52 mph (127.97 km/h) |
| 75 mph (120.7 km/h) | 85.2 mph (137.11 km/h) |
| 80 mph (128.75 km/h) | 90.88 mph (146.25 km/h) |
| 85 mph (136.79 km/h) | 96.56 mph (155.39 km/h) |
| 90 mph (144.84 km/h) | 102.24 mph (164.53 km/h) |
| 95 mph (152.89 km/h) | 107.91 mph (173.67 km/h) |
| 100 mph (160.93 km/h) | 113.59 mph (182.81 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1600 | 1859 | 2002 | 2090 | 2186 | 2254 | 2329 | 2417 | 2540 | 2662 | 2799 | 2907 | 3105 | 3323 | 3493 | 3602 | 3663 | 3888 | 4201 | 4882 |
Better Fuel Economy Factory Ratios Increased Power
