Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 155/85-18 | 255/45-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.37 (720.7) | 29.04 (737.5) | 0.66 (16.8) 2.3% |
| Width inches (mm) | 6.1 (155) | 10.04 (255) | 3.94 (100) 64.5% |
| Circum. inches (mm) | 89.14 (2264.15) | 91.22 (2316.92) | 2.08 (52.78) 2.3% |
| Sidewall Height inches (mm) | 5.19 (131.75) | 4.52 (114.75) | -0.67 (-17) -12.9% |
| Revolutions per mile (km) | 710.8 (441.67) | 694.6 (431.61) | -16.19 (-10.06) -2.3% |
255/45-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.47 mph (32.94 km/h) |
| 25 mph (40.23 km/h) | 25.58 mph (41.17 km/h) |
| 30 mph (48.28 km/h) | 30.7 mph (49.41 km/h) |
| 35 mph (56.33 km/h) | 35.82 mph (57.64 km/h) |
| 40 mph (64.37 km/h) | 40.93 mph (65.87 km/h) |
| 45 mph (72.42 km/h) | 46.05 mph (74.11 km/h) |
| 50 mph (80.47 km/h) | 51.17 mph (82.34 km/h) |
| 55 mph (88.51 km/h) | 56.28 mph (90.58 km/h) |
| 60 mph (96.56 km/h) | 61.4 mph (98.81 km/h) |
| 65 mph (104.61 km/h) | 66.52 mph (107.05 km/h) |
| 70 mph (112.65 km/h) | 71.63 mph (115.28 km/h) |
| 75 mph (120.7 km/h) | 76.75 mph (123.51 km/h) |
| 80 mph (128.75 km/h) | 81.86 mph (131.75 km/h) |
| 85 mph (136.79 km/h) | 86.98 mph (139.98 km/h) |
| 90 mph (144.84 km/h) | 92.1 mph (148.22 km/h) |
| 95 mph (152.89 km/h) | 97.21 mph (156.45 km/h) |
| 100 mph (160.93 km/h) | 102.33 mph (164.69 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1768 | 2053 | 2211 | 2309 | 2415 | 2490 | 2572 | 2670 | 2806 | 2941 | 3091 | 3212 | 3430 | 3671 | 3859 | 3979 | 4047 | 4295 | 4641 | 5393 |
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