Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 255/30-21 | 305/25-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.02 (686.4) | 27 (685.9) | -0.02 (-0.5) -0.1% |
| Width inches (mm) | 10.04 (255) | 12.01 (305) | 1.97 (50) 19.6% |
| Circum. inches (mm) | 84.9 (2156.39) | 84.84 (2154.82) | -0.06 (-1.57) -0.1% |
| Sidewall Height inches (mm) | 3.01 (76.5) | 3 (76.25) | -0.01 (-0.25) -0.3% |
| Revolutions per mile (km) | 746.31 (463.74) | 746.86 (464.08) | 0.54 (0.34) 0.1% |
305/25-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.99 mph (32.16 km/h) |
| 25 mph (40.23 km/h) | 24.98 mph (40.2 km/h) |
| 30 mph (48.28 km/h) | 29.98 mph (48.25 km/h) |
| 35 mph (56.33 km/h) | 34.97 mph (56.29 km/h) |
| 40 mph (64.37 km/h) | 39.97 mph (64.33 km/h) |
| 45 mph (72.42 km/h) | 44.97 mph (72.37 km/h) |
| 50 mph (80.47 km/h) | 49.96 mph (80.41 km/h) |
| 55 mph (88.51 km/h) | 54.96 mph (88.45 km/h) |
| 60 mph (96.56 km/h) | 59.96 mph (96.49 km/h) |
| 65 mph (104.61 km/h) | 64.95 mph (104.53 km/h) |
| 70 mph (112.65 km/h) | 69.95 mph (112.57 km/h) |
| 75 mph (120.7 km/h) | 74.95 mph (120.61 km/h) |
| 80 mph (128.75 km/h) | 79.94 mph (128.65 km/h) |
| 85 mph (136.79 km/h) | 84.94 mph (136.69 km/h) |
| 90 mph (144.84 km/h) | 89.93 mph (144.74 km/h) |
| 95 mph (152.89 km/h) | 94.93 mph (152.78 km/h) |
| 100 mph (160.93 km/h) | 99.93 mph (160.82 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1901 | 2208 | 2378 | 2483 | 2596 | 2677 | 2766 | 2871 | 3017 | 3162 | 3324 | 3453 | 3688 | 3947 | 4149 | 4278 | 4351 | 4618 | 4990 | 5799 |
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