Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 255/65-18 | 255/50-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 31.05 (788.7) | 31.04 (788.4) | -0.01 (-0.3) -0% |
| Width inches (mm) | 10.04 (255) | 10.04 (255) | 0 (0) 0% |
| Circum. inches (mm) | 97.55 (2477.77) | 97.51 (2476.83) | -0.04 (-0.94) -0% |
| Sidewall Height inches (mm) | 6.53 (165.75) | 5.02 (127.5) | -1.51 (-38.25) -23.1% |
| Revolutions per mile (km) | 649.51 (403.59) | 649.76 (403.74) | 0.25 (0.15) 0% |
255/50-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.99 mph (32.17 km/h) |
| 25 mph (40.23 km/h) | 24.99 mph (40.22 km/h) |
| 30 mph (48.28 km/h) | 29.99 mph (48.26 km/h) |
| 35 mph (56.33 km/h) | 34.99 mph (56.31 km/h) |
| 40 mph (64.37 km/h) | 39.98 mph (64.35 km/h) |
| 45 mph (72.42 km/h) | 44.98 mph (72.39 km/h) |
| 50 mph (80.47 km/h) | 49.98 mph (80.44 km/h) |
| 55 mph (88.51 km/h) | 54.98 mph (88.48 km/h) |
| 60 mph (96.56 km/h) | 59.98 mph (96.52 km/h) |
| 65 mph (104.61 km/h) | 64.98 mph (104.57 km/h) |
| 70 mph (112.65 km/h) | 69.97 mph (112.61 km/h) |
| 75 mph (120.7 km/h) | 74.97 mph (120.66 km/h) |
| 80 mph (128.75 km/h) | 79.97 mph (128.7 km/h) |
| 85 mph (136.79 km/h) | 84.97 mph (136.74 km/h) |
| 90 mph (144.84 km/h) | 89.97 mph (144.79 km/h) |
| 95 mph (152.89 km/h) | 94.96 mph (152.83 km/h) |
| 100 mph (160.93 km/h) | 99.96 mph (160.87 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1654 | 1921 | 2069 | 2160 | 2259 | 2329 | 2406 | 2498 | 2625 | 2751 | 2892 | 3004 | 3209 | 3434 | 3610 | 3722 | 3785 | 4018 | 4341 | 5045 |
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