Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 305/75-20 | 37/12.5-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 38.01 (965.5) | 37.03 (940.48) | -0.99 (-25.02) -2.6% |
| Width inches (mm) | 12.01 (305) | 12.52 (318) | 0.51 (13) 4.3% |
| Circum. inches (mm) | 119.42 (3033.21) | 116.32 (2954.61) | -3.09 (-78.6) -2.6% |
| Sidewall Height inches (mm) | 9.01 (228.75) | 8.51 (216.24) | -0.49 (-12.51) -5.5% |
| Revolutions per mile (km) | 530.57 (329.68) | 544.69 (338.45) | 14.12 (8.77) 2.7% |
37/12.5-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.48 mph (31.35 km/h) |
| 25 mph (40.23 km/h) | 24.35 mph (39.19 km/h) |
| 30 mph (48.28 km/h) | 29.22 mph (47.03 km/h) |
| 35 mph (56.33 km/h) | 34.09 mph (54.87 km/h) |
| 40 mph (64.37 km/h) | 38.96 mph (62.71 km/h) |
| 45 mph (72.42 km/h) | 43.83 mph (70.54 km/h) |
| 50 mph (80.47 km/h) | 48.7 mph (78.38 km/h) |
| 55 mph (88.51 km/h) | 53.57 mph (86.22 km/h) |
| 60 mph (96.56 km/h) | 58.45 mph (94.06 km/h) |
| 65 mph (104.61 km/h) | 63.32 mph (101.9 km/h) |
| 70 mph (112.65 km/h) | 68.19 mph (109.73 km/h) |
| 75 mph (120.7 km/h) | 73.06 mph (117.57 km/h) |
| 80 mph (128.75 km/h) | 77.93 mph (125.41 km/h) |
| 85 mph (136.79 km/h) | 82.8 mph (133.25 km/h) |
| 90 mph (144.84 km/h) | 87.67 mph (141.09 km/h) |
| 95 mph (152.89 km/h) | 92.54 mph (148.93 km/h) |
| 100 mph (160.93 km/h) | 97.41 mph (156.76 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 |
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