Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 305/30-21 | 275/30-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.2 (716.4) | 26.5 (673) | -1.71 (-43.4) -6.1% |
| Width inches (mm) | 12.01 (305) | 10.83 (275) | -1.18 (-30) -9.8% |
| Circum. inches (mm) | 88.61 (2250.64) | 83.24 (2114.29) | -5.37 (-136.35) -6.1% |
| Sidewall Height inches (mm) | 3.6 (91.5) | 3.25 (82.5) | -0.35 (-9) -9.8% |
| Revolutions per mile (km) | 715.06 (444.32) | 761.17 (472.97) | 46.11 (28.65) 6.4% |
275/30-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.79 mph (30.24 km/h) |
| 25 mph (40.23 km/h) | 23.49 mph (37.8 km/h) |
| 30 mph (48.28 km/h) | 28.18 mph (45.36 km/h) |
| 35 mph (56.33 km/h) | 32.88 mph (52.91 km/h) |
| 40 mph (64.37 km/h) | 37.58 mph (60.47 km/h) |
| 45 mph (72.42 km/h) | 42.27 mph (68.03 km/h) |
| 50 mph (80.47 km/h) | 46.97 mph (75.59 km/h) |
| 55 mph (88.51 km/h) | 51.67 mph (83.15 km/h) |
| 60 mph (96.56 km/h) | 56.37 mph (90.71 km/h) |
| 65 mph (104.61 km/h) | 61.06 mph (98.27 km/h) |
| 70 mph (112.65 km/h) | 65.76 mph (105.83 km/h) |
| 75 mph (120.7 km/h) | 70.46 mph (113.39 km/h) |
| 80 mph (128.75 km/h) | 75.15 mph (120.95 km/h) |
| 85 mph (136.79 km/h) | 79.85 mph (128.51 km/h) |
| 90 mph (144.84 km/h) | 84.55 mph (136.07 km/h) |
| 95 mph (152.89 km/h) | 89.24 mph (143.63 km/h) |
| 100 mph (160.93 km/h) | 93.94 mph (151.19 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1937 | 2250 | 2423 | 2531 | 2646 | 2728 | 2819 | 2926 | 3075 | 3223 | 3388 | 3520 | 3759 | 4022 | 4229 | 4360 | 4435 | 4707 | 5086 | 5910 |
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