Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 38/15.5-20 | 37/12.5-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 37.99 (965.04) | 37.03 (940.48) | -0.97 (-24.56) -2.5% |
| Width inches (mm) | 15.51 (394) | 12.52 (318) | -2.99 (-76) -19.3% |
| Circum. inches (mm) | 119.36 (3031.76) | 116.32 (2954.61) | -3.04 (-77.16) -2.5% |
| Sidewall Height inches (mm) | 9 (228.52) | 8.51 (216.24) | -0.48 (-12.28) -5.4% |
| Revolutions per mile (km) | 530.83 (329.84) | 544.69 (338.45) | 13.86 (8.61) 2.6% |
37/12.5-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.49 mph (31.37 km/h) |
| 25 mph (40.23 km/h) | 24.36 mph (39.21 km/h) |
| 30 mph (48.28 km/h) | 29.24 mph (47.05 km/h) |
| 35 mph (56.33 km/h) | 34.11 mph (54.89 km/h) |
| 40 mph (64.37 km/h) | 38.98 mph (62.74 km/h) |
| 45 mph (72.42 km/h) | 43.85 mph (70.58 km/h) |
| 50 mph (80.47 km/h) | 48.73 mph (78.42 km/h) |
| 55 mph (88.51 km/h) | 53.6 mph (86.26 km/h) |
| 60 mph (96.56 km/h) | 58.47 mph (94.1 km/h) |
| 65 mph (104.61 km/h) | 63.35 mph (101.95 km/h) |
| 70 mph (112.65 km/h) | 68.22 mph (109.79 km/h) |
| 75 mph (120.7 km/h) | 73.09 mph (117.63 km/h) |
| 80 mph (128.75 km/h) | 77.96 mph (125.47 km/h) |
| 85 mph (136.79 km/h) | 82.84 mph (133.31 km/h) |
| 90 mph (144.84 km/h) | 87.71 mph (141.16 km/h) |
| 95 mph (152.89 km/h) | 92.58 mph (149 km/h) |
| 100 mph (160.93 km/h) | 97.46 mph (156.84 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
