Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 170/55-17 | 255/55-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 24.36 (618.8) | 31.04 (788.5) | 6.68 (169.7) 27.4% |
| Width inches (mm) | 6.69 (170) | 10.04 (255) | 3.35 (85) 50% |
| Circum. inches (mm) | 76.54 (1944.02) | 97.53 (2477.15) | 20.99 (533.13) 27.4% |
| Sidewall Height inches (mm) | 3.68 (93.5) | 5.52 (140.25) | 1.84 (46.75) 50% |
| Revolutions per mile (km) | 827.84 (514.4) | 649.68 (403.69) | -178.17 (-110.71) -21.5% |
255/55-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 25.48 mph (41.01 km/h) |
| 25 mph (40.23 km/h) | 31.86 mph (51.27 km/h) |
| 30 mph (48.28 km/h) | 38.23 mph (61.52 km/h) |
| 35 mph (56.33 km/h) | 44.6 mph (71.77 km/h) |
| 40 mph (64.37 km/h) | 50.97 mph (82.03 km/h) |
| 45 mph (72.42 km/h) | 57.34 mph (92.28 km/h) |
| 50 mph (80.47 km/h) | 63.71 mph (102.53 km/h) |
| 55 mph (88.51 km/h) | 70.08 mph (112.79 km/h) |
| 60 mph (96.56 km/h) | 76.45 mph (123.04 km/h) |
| 65 mph (104.61 km/h) | 82.83 mph (133.3 km/h) |
| 70 mph (112.65 km/h) | 89.2 mph (143.55 km/h) |
| 75 mph (120.7 km/h) | 95.57 mph (153.8 km/h) |
| 80 mph (128.75 km/h) | 101.94 mph (164.06 km/h) |
| 85 mph (136.79 km/h) | 108.31 mph (174.31 km/h) |
| 90 mph (144.84 km/h) | 114.68 mph (184.56 km/h) |
| 95 mph (152.89 km/h) | 121.05 mph (194.82 km/h) |
| 100 mph (160.93 km/h) | 127.42 mph (205.07 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1653 | 1921 | 2068 | 2160 | 2258 | 2329 | 2406 | 2498 | 2624 | 2751 | 2892 | 3004 | 3208 | 3433 | 3609 | 3722 | 3785 | 4017 | 4341 | 5044 |
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