Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/70-18 | 37/12.5-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 35.91 (912.2) | 37.03 (940.56) | 1.12 (28.36) 3.1% |
| Width inches (mm) | 12.8 (325) | 12.52 (318) | -0.28 (-7) -2.2% |
| Circum. inches (mm) | 112.83 (2865.76) | 116.33 (2954.86) | 3.51 (89.1) 3.1% |
| Sidewall Height inches (mm) | 8.96 (227.5) | 9.51 (241.68) | 0.56 (14.18) 6.2% |
| Revolutions per mile (km) | 561.58 (348.95) | 544.64 (338.43) | -16.93 (-10.52) -3% |
37/12.5-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.62 mph (33.19 km/h) |
| 25 mph (40.23 km/h) | 25.78 mph (41.48 km/h) |
| 30 mph (48.28 km/h) | 30.93 mph (49.78 km/h) |
| 35 mph (56.33 km/h) | 36.09 mph (58.08 km/h) |
| 40 mph (64.37 km/h) | 41.24 mph (66.38 km/h) |
| 45 mph (72.42 km/h) | 46.4 mph (74.67 km/h) |
| 50 mph (80.47 km/h) | 51.55 mph (82.97 km/h) |
| 55 mph (88.51 km/h) | 56.71 mph (91.27 km/h) |
| 60 mph (96.56 km/h) | 61.87 mph (99.56 km/h) |
| 65 mph (104.61 km/h) | 67.02 mph (107.86 km/h) |
| 70 mph (112.65 km/h) | 72.18 mph (116.16 km/h) |
| 75 mph (120.7 km/h) | 77.33 mph (124.45 km/h) |
| 80 mph (128.75 km/h) | 82.49 mph (132.75 km/h) |
| 85 mph (136.79 km/h) | 87.64 mph (141.05 km/h) |
| 90 mph (144.84 km/h) | 92.8 mph (149.34 km/h) |
| 95 mph (152.89 km/h) | 97.95 mph (157.64 km/h) |
| 100 mph (160.93 km/h) | 103.11 mph (165.94 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1386 | 1610 | 1734 | 1811 | 1893 | 1952 | 2017 | 2094 | 2200 | 2306 | 2424 | 2518 | 2689 | 2878 | 3026 | 3120 | 3173 | 3368 | 3639 | 4229 |
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