Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 285/30-21 | 275/30-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.73 (704.4) | 27.5 (698.4) | -0.24 (-6) -0.9% |
| Width inches (mm) | 11.22 (285) | 10.83 (275) | -0.39 (-10) -3.5% |
| Circum. inches (mm) | 87.12 (2212.94) | 86.38 (2194.09) | -0.74 (-18.85) -0.9% |
| Sidewall Height inches (mm) | 3.37 (85.5) | 3.25 (82.5) | -0.12 (-3) -3.5% |
| Revolutions per mile (km) | 727.24 (451.89) | 733.49 (455.77) | 6.25 (3.88) 0.9% |
275/30-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.83 mph (31.91 km/h) |
| 25 mph (40.23 km/h) | 24.79 mph (39.89 km/h) |
| 30 mph (48.28 km/h) | 29.74 mph (47.87 km/h) |
| 35 mph (56.33 km/h) | 34.7 mph (55.85 km/h) |
| 40 mph (64.37 km/h) | 39.66 mph (63.83 km/h) |
| 45 mph (72.42 km/h) | 44.62 mph (71.8 km/h) |
| 50 mph (80.47 km/h) | 49.57 mph (79.78 km/h) |
| 55 mph (88.51 km/h) | 54.53 mph (87.76 km/h) |
| 60 mph (96.56 km/h) | 59.49 mph (95.74 km/h) |
| 65 mph (104.61 km/h) | 64.45 mph (103.72 km/h) |
| 70 mph (112.65 km/h) | 69.4 mph (111.69 km/h) |
| 75 mph (120.7 km/h) | 74.36 mph (119.67 km/h) |
| 80 mph (128.75 km/h) | 79.32 mph (127.65 km/h) |
| 85 mph (136.79 km/h) | 84.28 mph (135.63 km/h) |
| 90 mph (144.84 km/h) | 89.23 mph (143.61 km/h) |
| 95 mph (152.89 km/h) | 94.19 mph (151.59 km/h) |
| 100 mph (160.93 km/h) | 99.15 mph (159.56 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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