Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/40-18 | 325/65-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.24 (717.2) | 34.63 (879.7) | 6.4 (162.5) 22.7% |
| Width inches (mm) | 12.8 (325) | 12.8 (325) | 0 (0) 0% |
| Circum. inches (mm) | 88.71 (2253.15) | 108.81 (2763.66) | 20.1 (510.51) 22.7% |
| Sidewall Height inches (mm) | 5.12 (130) | 8.32 (211.25) | 3.2 (81.25) 62.5% |
| Revolutions per mile (km) | 714.26 (443.82) | 582.32 (361.84) | -131.94 (-81.98) -18.5% |
325/65-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 24.53 mph (39.48 km/h) |
| 25 mph (40.23 km/h) | 30.66 mph (49.35 km/h) |
| 30 mph (48.28 km/h) | 36.8 mph (59.22 km/h) |
| 35 mph (56.33 km/h) | 42.93 mph (69.09 km/h) |
| 40 mph (64.37 km/h) | 49.06 mph (78.96 km/h) |
| 45 mph (72.42 km/h) | 55.2 mph (88.83 km/h) |
| 50 mph (80.47 km/h) | 61.33 mph (98.7 km/h) |
| 55 mph (88.51 km/h) | 67.46 mph (108.57 km/h) |
| 60 mph (96.56 km/h) | 73.59 mph (118.44 km/h) |
| 65 mph (104.61 km/h) | 79.73 mph (128.31 km/h) |
| 70 mph (112.65 km/h) | 85.86 mph (138.18 km/h) |
| 75 mph (120.7 km/h) | 91.99 mph (148.05 km/h) |
| 80 mph (128.75 km/h) | 98.13 mph (157.92 km/h) |
| 85 mph (136.79 km/h) | 104.26 mph (167.79 km/h) |
| 90 mph (144.84 km/h) | 110.39 mph (177.66 km/h) |
| 95 mph (152.89 km/h) | 116.52 mph (187.53 km/h) |
| 100 mph (160.93 km/h) | 122.66 mph (197.4 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1482 | 1722 | 1854 | 1936 | 2024 | 2087 | 2157 | 2239 | 2352 | 2466 | 2592 | 2693 | 2876 | 3077 | 3235 | 3336 | 3393 | 3601 | 3891 | 4521 |
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