Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/80-15 | 37/12.5-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 35.47 (901) | 37.03 (940.56) | 1.56 (39.56) 4.4% |
| Width inches (mm) | 12.8 (325) | 12.52 (318) | -0.28 (-7) -2.2% |
| Circum. inches (mm) | 111.44 (2830.57) | 116.33 (2954.86) | 4.89 (124.28) 4.4% |
| Sidewall Height inches (mm) | 10.24 (260) | 9.51 (241.68) | -0.72 (-18.32) -7% |
| Revolutions per mile (km) | 568.56 (353.28) | 544.64 (338.43) | -23.91 (-14.86) -4.2% |
37/12.5-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.88 mph (33.6 km/h) |
| 25 mph (40.23 km/h) | 26.1 mph (42 km/h) |
| 30 mph (48.28 km/h) | 31.32 mph (50.4 km/h) |
| 35 mph (56.33 km/h) | 36.54 mph (58.8 km/h) |
| 40 mph (64.37 km/h) | 41.76 mph (67.2 km/h) |
| 45 mph (72.42 km/h) | 46.98 mph (75.6 km/h) |
| 50 mph (80.47 km/h) | 52.2 mph (84 km/h) |
| 55 mph (88.51 km/h) | 57.41 mph (92.4 km/h) |
| 60 mph (96.56 km/h) | 62.63 mph (100.8 km/h) |
| 65 mph (104.61 km/h) | 67.85 mph (109.2 km/h) |
| 70 mph (112.65 km/h) | 73.07 mph (117.6 km/h) |
| 75 mph (120.7 km/h) | 78.29 mph (126 km/h) |
| 80 mph (128.75 km/h) | 83.51 mph (134.4 km/h) |
| 85 mph (136.79 km/h) | 88.73 mph (142.8 km/h) |
| 90 mph (144.84 km/h) | 93.95 mph (151.2 km/h) |
| 95 mph (152.89 km/h) | 99.17 mph (159.6 km/h) |
| 100 mph (160.93 km/h) | 104.39 mph (168 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 |
Better Fuel Economy Factory Ratios Increased Power
