Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/60-20 | 37/12.5-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 35.35 (898) | 37.03 (940.48) | 1.67 (42.48) 4.7% |
| Width inches (mm) | 12.8 (325) | 12.52 (318) | -0.28 (-7) -2.2% |
| Circum. inches (mm) | 111.07 (2821.15) | 116.32 (2954.61) | 5.25 (133.45) 4.7% |
| Sidewall Height inches (mm) | 7.68 (195) | 8.51 (216.24) | 0.84 (21.24) 10.9% |
| Revolutions per mile (km) | 570.46 (354.46) | 544.69 (338.45) | -25.77 (-16.01) -4.5% |
37/12.5-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.95 mph (33.71 km/h) |
| 25 mph (40.23 km/h) | 26.18 mph (42.14 km/h) |
| 30 mph (48.28 km/h) | 31.42 mph (50.56 km/h) |
| 35 mph (56.33 km/h) | 36.66 mph (58.99 km/h) |
| 40 mph (64.37 km/h) | 41.89 mph (67.42 km/h) |
| 45 mph (72.42 km/h) | 47.13 mph (75.85 km/h) |
| 50 mph (80.47 km/h) | 52.37 mph (84.27 km/h) |
| 55 mph (88.51 km/h) | 57.6 mph (92.7 km/h) |
| 60 mph (96.56 km/h) | 62.84 mph (101.13 km/h) |
| 65 mph (104.61 km/h) | 68.07 mph (109.56 km/h) |
| 70 mph (112.65 km/h) | 73.31 mph (117.98 km/h) |
| 75 mph (120.7 km/h) | 78.55 mph (126.41 km/h) |
| 80 mph (128.75 km/h) | 83.78 mph (134.84 km/h) |
| 85 mph (136.79 km/h) | 89.02 mph (143.27 km/h) |
| 90 mph (144.84 km/h) | 94.26 mph (151.69 km/h) |
| 95 mph (152.89 km/h) | 99.49 mph (160.12 km/h) |
| 100 mph (160.93 km/h) | 104.73 mph (168.55 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
