Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/40-18 | 285/45-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.24 (717.2) | 28.1 (713.7) | -0.14 (-3.5) -0.5% |
| Width inches (mm) | 12.8 (325) | 11.22 (285) | -1.57 (-40) -12.3% |
| Circum. inches (mm) | 88.71 (2253.15) | 88.27 (2242.15) | -0.43 (-11) -0.5% |
| Sidewall Height inches (mm) | 5.12 (130) | 5.05 (128.25) | -0.07 (-1.75) -1.3% |
| Revolutions per mile (km) | 714.26 (443.82) | 717.77 (446) | 3.5 (2.18) 0.5% |
285/45-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.9 mph (32.03 km/h) |
| 25 mph (40.23 km/h) | 24.88 mph (40.04 km/h) |
| 30 mph (48.28 km/h) | 29.85 mph (48.04 km/h) |
| 35 mph (56.33 km/h) | 34.83 mph (56.05 km/h) |
| 40 mph (64.37 km/h) | 39.8 mph (64.06 km/h) |
| 45 mph (72.42 km/h) | 44.78 mph (72.07 km/h) |
| 50 mph (80.47 km/h) | 49.76 mph (80.07 km/h) |
| 55 mph (88.51 km/h) | 54.73 mph (88.08 km/h) |
| 60 mph (96.56 km/h) | 59.71 mph (96.09 km/h) |
| 65 mph (104.61 km/h) | 64.68 mph (104.1 km/h) |
| 70 mph (112.65 km/h) | 69.66 mph (112.1 km/h) |
| 75 mph (120.7 km/h) | 74.63 mph (120.11 km/h) |
| 80 mph (128.75 km/h) | 79.61 mph (128.12 km/h) |
| 85 mph (136.79 km/h) | 84.59 mph (136.13 km/h) |
| 90 mph (144.84 km/h) | 89.56 mph (144.13 km/h) |
| 95 mph (152.89 km/h) | 94.54 mph (152.14 km/h) |
| 100 mph (160.93 km/h) | 99.51 mph (160.15 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1827 | 2122 | 2285 | 2386 | 2495 | 2573 | 2658 | 2759 | 2899 | 3039 | 3195 | 3319 | 3544 | 3793 | 3987 | 4112 | 4182 | 4438 | 4796 | 5573 |
Better Fuel Economy Factory Ratios Increased Power
