Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/70-18 | 38/13.5-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 35.91 (912.2) | 37.99 (964.84) | 2.07 (52.64) 5.8% |
| Width inches (mm) | 12.8 (325) | 13.5 (343) | 0.71 (18) 5.5% |
| Circum. inches (mm) | 112.83 (2865.76) | 119.34 (3031.13) | 6.51 (165.37) 5.8% |
| Sidewall Height inches (mm) | 8.96 (227.5) | 9.99 (253.82) | 1.04 (26.32) 11.6% |
| Revolutions per mile (km) | 561.58 (348.95) | 530.94 (329.91) | -30.64 (-19.04) -5.5% |
38/13.5-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.15 mph (34.04 km/h) |
| 25 mph (40.23 km/h) | 26.44 mph (42.56 km/h) |
| 30 mph (48.28 km/h) | 31.73 mph (51.07 km/h) |
| 35 mph (56.33 km/h) | 37.02 mph (59.58 km/h) |
| 40 mph (64.37 km/h) | 42.31 mph (68.09 km/h) |
| 45 mph (72.42 km/h) | 47.6 mph (76.6 km/h) |
| 50 mph (80.47 km/h) | 52.89 mph (85.11 km/h) |
| 55 mph (88.51 km/h) | 58.17 mph (93.62 km/h) |
| 60 mph (96.56 km/h) | 63.46 mph (102.13 km/h) |
| 65 mph (104.61 km/h) | 68.75 mph (110.64 km/h) |
| 70 mph (112.65 km/h) | 74.04 mph (119.16 km/h) |
| 75 mph (120.7 km/h) | 79.33 mph (127.67 km/h) |
| 80 mph (128.75 km/h) | 84.62 mph (136.18 km/h) |
| 85 mph (136.79 km/h) | 89.91 mph (144.69 km/h) |
| 90 mph (144.84 km/h) | 95.19 mph (153.2 km/h) |
| 95 mph (152.89 km/h) | 100.48 mph (161.71 km/h) |
| 100 mph (160.93 km/h) | 105.77 mph (170.22 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1351 | 1570 | 1690 | 1765 | 1846 | 1903 | 1966 | 2041 | 2145 | 2248 | 2363 | 2455 | 2622 | 2806 | 2950 | 3041 | 3093 | 3283 | 3547 | 4122 |
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