Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 305/25-21 | 275/30-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27 (685.9) | 27.5 (698.4) | 0.49 (12.5) 1.8% |
| Width inches (mm) | 12.01 (305) | 10.83 (275) | -1.18 (-30) -9.8% |
| Circum. inches (mm) | 84.84 (2154.82) | 86.38 (2194.09) | 1.55 (39.27) 1.8% |
| Sidewall Height inches (mm) | 3 (76.25) | 3.25 (82.5) | 0.25 (6.25) 8.2% |
| Revolutions per mile (km) | 746.86 (464.08) | 733.49 (455.77) | -13.37 (-8.31) -1.8% |
275/30-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.36 mph (32.77 km/h) |
| 25 mph (40.23 km/h) | 25.46 mph (40.97 km/h) |
| 30 mph (48.28 km/h) | 30.55 mph (49.16 km/h) |
| 35 mph (56.33 km/h) | 35.64 mph (57.35 km/h) |
| 40 mph (64.37 km/h) | 40.73 mph (65.55 km/h) |
| 45 mph (72.42 km/h) | 45.82 mph (73.74 km/h) |
| 50 mph (80.47 km/h) | 50.91 mph (81.93 km/h) |
| 55 mph (88.51 km/h) | 56 mph (90.13 km/h) |
| 60 mph (96.56 km/h) | 61.09 mph (98.32 km/h) |
| 65 mph (104.61 km/h) | 66.18 mph (106.51 km/h) |
| 70 mph (112.65 km/h) | 71.28 mph (114.71 km/h) |
| 75 mph (120.7 km/h) | 76.37 mph (122.9 km/h) |
| 80 mph (128.75 km/h) | 81.46 mph (131.09 km/h) |
| 85 mph (136.79 km/h) | 86.55 mph (139.29 km/h) |
| 90 mph (144.84 km/h) | 91.64 mph (147.48 km/h) |
| 95 mph (152.89 km/h) | 96.73 mph (155.67 km/h) |
| 100 mph (160.93 km/h) | 101.82 mph (163.87 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1867 | 2168 | 2335 | 2438 | 2550 | 2629 | 2716 | 2820 | 2963 | 3106 | 3265 | 3392 | 3622 | 3876 | 4075 | 4202 | 4273 | 4535 | 4901 | 5695 |
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