Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 305/70-18 | 305/55-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 34.81 (884.2) | 33.21 (843.5) | -1.6 (-40.7) -4.6% |
| Width inches (mm) | 12.01 (305) | 12.01 (305) | 0 (0) 0% |
| Circum. inches (mm) | 109.36 (2777.8) | 104.33 (2649.93) | -5.03 (-127.86) -4.6% |
| Sidewall Height inches (mm) | 8.41 (213.5) | 6.6 (167.75) | -1.8 (-45.75) -21.4% |
| Revolutions per mile (km) | 579.36 (360) | 607.31 (377.37) | 27.95 (17.37) 4.8% |
305/55-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.08 mph (30.71 km/h) |
| 25 mph (40.23 km/h) | 23.85 mph (38.38 km/h) |
| 30 mph (48.28 km/h) | 28.62 mph (46.06 km/h) |
| 35 mph (56.33 km/h) | 33.39 mph (53.73 km/h) |
| 40 mph (64.37 km/h) | 38.16 mph (61.41 km/h) |
| 45 mph (72.42 km/h) | 42.93 mph (69.09 km/h) |
| 50 mph (80.47 km/h) | 47.7 mph (76.76 km/h) |
| 55 mph (88.51 km/h) | 52.47 mph (84.44 km/h) |
| 60 mph (96.56 km/h) | 57.24 mph (92.12 km/h) |
| 65 mph (104.61 km/h) | 62.01 mph (99.79 km/h) |
| 70 mph (112.65 km/h) | 66.78 mph (107.47 km/h) |
| 75 mph (120.7 km/h) | 71.55 mph (115.15 km/h) |
| 80 mph (128.75 km/h) | 76.32 mph (122.82 km/h) |
| 85 mph (136.79 km/h) | 81.09 mph (130.5 km/h) |
| 90 mph (144.84 km/h) | 85.86 mph (138.17 km/h) |
| 95 mph (152.89 km/h) | 90.63 mph (145.85 km/h) |
| 100 mph (160.93 km/h) | 95.4 mph (153.53 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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