Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/40-18 | 255/50-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.24 (717.2) | 30.04 (763) | 1.8 (45.8) 6.4% |
| Width inches (mm) | 12.8 (325) | 10.04 (255) | -2.76 (-70) -21.5% |
| Circum. inches (mm) | 88.71 (2253.15) | 94.37 (2397.04) | 5.66 (143.88) 6.4% |
| Sidewall Height inches (mm) | 5.12 (130) | 5.02 (127.5) | -0.1 (-2.5) -1.9% |
| Revolutions per mile (km) | 714.26 (443.82) | 671.39 (417.18) | -42.87 (-26.64) -6% |
255/50-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.28 mph (34.24 km/h) |
| 25 mph (40.23 km/h) | 26.6 mph (42.8 km/h) |
| 30 mph (48.28 km/h) | 31.92 mph (51.36 km/h) |
| 35 mph (56.33 km/h) | 37.24 mph (59.92 km/h) |
| 40 mph (64.37 km/h) | 42.55 mph (68.48 km/h) |
| 45 mph (72.42 km/h) | 47.87 mph (77.05 km/h) |
| 50 mph (80.47 km/h) | 53.19 mph (85.61 km/h) |
| 55 mph (88.51 km/h) | 58.51 mph (94.17 km/h) |
| 60 mph (96.56 km/h) | 63.83 mph (102.73 km/h) |
| 65 mph (104.61 km/h) | 69.15 mph (111.29 km/h) |
| 70 mph (112.65 km/h) | 74.47 mph (119.85 km/h) |
| 75 mph (120.7 km/h) | 79.79 mph (128.41 km/h) |
| 80 mph (128.75 km/h) | 85.11 mph (136.97 km/h) |
| 85 mph (136.79 km/h) | 90.43 mph (145.53 km/h) |
| 90 mph (144.84 km/h) | 95.75 mph (154.09 km/h) |
| 95 mph (152.89 km/h) | 101.07 mph (162.65 km/h) |
| 100 mph (160.93 km/h) | 106.39 mph (171.21 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1709 | 1985 | 2138 | 2232 | 2334 | 2407 | 2486 | 2581 | 2712 | 2843 | 2988 | 3104 | 3315 | 3548 | 3730 | 3846 | 3912 | 4151 | 4486 | 5213 |
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