Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 38/15.5-20 | 305/55-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 37.99 (965.04) | 33.21 (843.5) | -4.79 (-121.54) -12.6% |
| Width inches (mm) | 15.51 (394) | 12.01 (305) | -3.5 (-89) -22.6% |
| Circum. inches (mm) | 119.36 (3031.76) | 104.33 (2649.93) | -15.03 (-381.83) -12.6% |
| Sidewall Height inches (mm) | 9 (228.52) | 6.6 (167.75) | -2.39 (-60.77) -26.6% |
| Revolutions per mile (km) | 530.83 (329.84) | 607.31 (377.37) | 76.49 (47.53) 14.4% |
305/55-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 17.48 mph (28.13 km/h) |
| 25 mph (40.23 km/h) | 21.85 mph (35.17 km/h) |
| 30 mph (48.28 km/h) | 26.22 mph (42.2 km/h) |
| 35 mph (56.33 km/h) | 30.59 mph (49.23 km/h) |
| 40 mph (64.37 km/h) | 34.96 mph (56.27 km/h) |
| 45 mph (72.42 km/h) | 39.33 mph (63.3 km/h) |
| 50 mph (80.47 km/h) | 43.7 mph (70.33 km/h) |
| 55 mph (88.51 km/h) | 48.07 mph (77.37 km/h) |
| 60 mph (96.56 km/h) | 52.44 mph (84.4 km/h) |
| 65 mph (104.61 km/h) | 56.81 mph (91.43 km/h) |
| 70 mph (112.65 km/h) | 61.18 mph (98.47 km/h) |
| 75 mph (120.7 km/h) | 65.55 mph (105.5 km/h) |
| 80 mph (128.75 km/h) | 69.92 mph (112.53 km/h) |
| 85 mph (136.79 km/h) | 74.29 mph (119.57 km/h) |
| 90 mph (144.84 km/h) | 78.67 mph (126.6 km/h) |
| 95 mph (152.89 km/h) | 83.04 mph (133.63 km/h) |
| 100 mph (160.93 km/h) | 87.41 mph (140.67 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1546 | 1795 | 1934 | 2019 | 2111 | 2177 | 2249 | 2335 | 2453 | 2571 | 2703 | 2808 | 2999 | 3209 | 3374 | 3479 | 3538 | 3755 | 4058 | 4715 |
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