Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 305/30-21 | 275/30-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.2 (716.4) | 27.5 (698.4) | -0.71 (-18) -2.5% |
| Width inches (mm) | 12.01 (305) | 10.83 (275) | -1.18 (-30) -9.8% |
| Circum. inches (mm) | 88.61 (2250.64) | 86.38 (2194.09) | -2.23 (-56.55) -2.5% |
| 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) | 733.49 (455.77) | 18.43 (11.45) 2.6% |
275/30-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.5 mph (31.38 km/h) |
| 25 mph (40.23 km/h) | 24.37 mph (39.22 km/h) |
| 30 mph (48.28 km/h) | 29.25 mph (47.07 km/h) |
| 35 mph (56.33 km/h) | 34.12 mph (54.91 km/h) |
| 40 mph (64.37 km/h) | 38.99 mph (62.76 km/h) |
| 45 mph (72.42 km/h) | 43.87 mph (70.6 km/h) |
| 50 mph (80.47 km/h) | 48.74 mph (78.45 km/h) |
| 55 mph (88.51 km/h) | 53.62 mph (86.29 km/h) |
| 60 mph (96.56 km/h) | 58.49 mph (94.13 km/h) |
| 65 mph (104.61 km/h) | 63.37 mph (101.98 km/h) |
| 70 mph (112.65 km/h) | 68.24 mph (109.82 km/h) |
| 75 mph (120.7 km/h) | 73.12 mph (117.67 km/h) |
| 80 mph (128.75 km/h) | 77.99 mph (125.51 km/h) |
| 85 mph (136.79 km/h) | 82.86 mph (133.36 km/h) |
| 90 mph (144.84 km/h) | 87.74 mph (141.2 km/h) |
| 95 mph (152.89 km/h) | 92.61 mph (149.05 km/h) |
| 100 mph (160.93 km/h) | 97.49 mph (156.89 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 |
Better Fuel Economy Factory Ratios Increased Power
