Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/70-16 | 37/12.5-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 33.91 (861.4) | 37.03 (940.48) | 3.11 (79.08) 9.2% |
| Width inches (mm) | 12.8 (325) | 12.52 (318) | -0.28 (-7) -2.2% |
| Circum. inches (mm) | 106.54 (2706.17) | 116.32 (2954.61) | 9.78 (248.44) 9.2% |
| Sidewall Height inches (mm) | 8.96 (227.5) | 8.51 (216.24) | -0.44 (-11.26) -4.9% |
| Revolutions per mile (km) | 594.69 (369.53) | 544.69 (338.45) | -50 (-31.07) -8.4% |
37/12.5-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.84 mph (35.14 km/h) |
| 25 mph (40.23 km/h) | 27.3 mph (43.93 km/h) |
| 30 mph (48.28 km/h) | 32.75 mph (52.71 km/h) |
| 35 mph (56.33 km/h) | 38.21 mph (61.5 km/h) |
| 40 mph (64.37 km/h) | 43.67 mph (70.28 km/h) |
| 45 mph (72.42 km/h) | 49.13 mph (79.07 km/h) |
| 50 mph (80.47 km/h) | 54.59 mph (87.85 km/h) |
| 55 mph (88.51 km/h) | 60.05 mph (96.64 km/h) |
| 60 mph (96.56 km/h) | 65.51 mph (105.43 km/h) |
| 65 mph (104.61 km/h) | 70.97 mph (114.21 km/h) |
| 70 mph (112.65 km/h) | 76.43 mph (123 km/h) |
| 75 mph (120.7 km/h) | 81.89 mph (131.78 km/h) |
| 80 mph (128.75 km/h) | 87.34 mph (140.57 km/h) |
| 85 mph (136.79 km/h) | 92.8 mph (149.35 km/h) |
| 90 mph (144.84 km/h) | 98.26 mph (158.14 km/h) |
| 95 mph (152.89 km/h) | 103.72 mph (166.92 km/h) |
| 100 mph (160.93 km/h) | 109.18 mph (175.71 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 | 2519 | 2690 | 2878 | 3026 | 3120 | 3173 | 3368 | 3639 | 4229 |
Better Fuel Economy Factory Ratios Increased Power
