Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 395/85-20 | 39/12.5-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 46.44 (1179.5) | 39.03 (991.36) | -7.41 (-188.14) -16% |
| Width inches (mm) | 15.55 (395) | 12.52 (318) | -3.03 (-77) -19.5% |
| Circum. inches (mm) | 145.89 (3705.51) | 122.62 (3114.45) | -23.27 (-591.06) -16% |
| Sidewall Height inches (mm) | 13.22 (335.75) | 9.51 (241.68) | -3.7 (-94.07) -28% |
| Revolutions per mile (km) | 434.31 (269.87) | 516.73 (321.08) | 82.42 (51.22) 19% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 16.81 mph (27.05 km/h) |
| 25 mph (40.23 km/h) | 21.01 mph (33.82 km/h) |
| 30 mph (48.28 km/h) | 25.21 mph (40.58 km/h) |
| 35 mph (56.33 km/h) | 29.42 mph (47.34 km/h) |
| 40 mph (64.37 km/h) | 33.62 mph (54.11 km/h) |
| 45 mph (72.42 km/h) | 37.82 mph (60.87 km/h) |
| 50 mph (80.47 km/h) | 42.02 mph (67.63 km/h) |
| 55 mph (88.51 km/h) | 46.23 mph (74.4 km/h) |
| 60 mph (96.56 km/h) | 50.43 mph (81.16 km/h) |
| 65 mph (104.61 km/h) | 54.63 mph (87.92 km/h) |
| 70 mph (112.65 km/h) | 58.83 mph (94.69 km/h) |
| 75 mph (120.7 km/h) | 63.04 mph (101.45 km/h) |
| 80 mph (128.75 km/h) | 67.24 mph (108.21 km/h) |
| 85 mph (136.79 km/h) | 71.44 mph (114.97 km/h) |
| 90 mph (144.84 km/h) | 75.64 mph (121.74 km/h) |
| 95 mph (152.89 km/h) | 79.85 mph (128.5 km/h) |
| 100 mph (160.93 km/h) | 84.05 mph (135.26 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1315 | 1528 | 1645 | 1718 | 1796 | 1852 | 1914 | 1986 | 2087 | 2188 | 2300 | 2389 | 2552 | 2731 | 2871 | 2960 | 3010 | 3195 | 3453 | 4012 |
Better Fuel Economy Factory Ratios Increased Power
