Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/40-18 | 225/45-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.24 (717.2) | 25.97 (659.7) | -2.26 (-57.5) -8% |
| Width inches (mm) | 12.8 (325) | 8.86 (225) | -3.94 (-100) -30.8% |
| Circum. inches (mm) | 88.71 (2253.15) | 81.59 (2072.51) | -7.11 (-180.64) -8% |
| Sidewall Height inches (mm) | 5.12 (130) | 3.99 (101.25) | -1.13 (-28.75) -22.1% |
| Revolutions per mile (km) | 714.26 (443.82) | 776.52 (482.51) | 62.26 (38.68) 8.7% |
225/45-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.4 mph (29.61 km/h) |
| 25 mph (40.23 km/h) | 23 mph (37.01 km/h) |
| 30 mph (48.28 km/h) | 27.59 mph (44.41 km/h) |
| 35 mph (56.33 km/h) | 32.19 mph (51.81 km/h) |
| 40 mph (64.37 km/h) | 36.79 mph (59.21 km/h) |
| 45 mph (72.42 km/h) | 41.39 mph (66.61 km/h) |
| 50 mph (80.47 km/h) | 45.99 mph (74.02 km/h) |
| 55 mph (88.51 km/h) | 50.59 mph (81.42 km/h) |
| 60 mph (96.56 km/h) | 55.19 mph (88.82 km/h) |
| 65 mph (104.61 km/h) | 59.79 mph (96.22 km/h) |
| 70 mph (112.65 km/h) | 64.39 mph (103.62 km/h) |
| 75 mph (120.7 km/h) | 68.99 mph (111.02 km/h) |
| 80 mph (128.75 km/h) | 73.59 mph (118.43 km/h) |
| 85 mph (136.79 km/h) | 78.19 mph (125.83 km/h) |
| 90 mph (144.84 km/h) | 82.78 mph (133.23 km/h) |
| 95 mph (152.89 km/h) | 87.38 mph (140.63 km/h) |
| 100 mph (160.93 km/h) | 91.98 mph (148.03 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1976 | 2296 | 2472 | 2582 | 2699 | 2783 | 2876 | 2985 | 3137 | 3288 | 3456 | 3591 | 3834 | 4104 | 4314 | 4448 | 4524 | 4801 | 5188 | 6029 |
Better Fuel Economy Factory Ratios Increased Power
