Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 120/70-21 | 120/80-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.61 (701.4) | 28.56 (725.4) | 0.94 (24) 3.4% |
| Width inches (mm) | 4.72 (120) | 4.72 (120) | 0 (0) 0% |
| Circum. inches (mm) | 86.75 (2203.51) | 89.72 (2278.91) | 2.97 (75.4) 3.4% |
| Sidewall Height inches (mm) | 3.31 (84) | 3.78 (96) | 0.47 (12) 14.3% |
| Revolutions per mile (km) | 730.35 (453.82) | 706.19 (438.81) | -24.16 (-15.01) -3.3% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.68 mph (33.29 km/h) |
| 25 mph (40.23 km/h) | 25.86 mph (41.61 km/h) |
| 30 mph (48.28 km/h) | 31.03 mph (49.93 km/h) |
| 35 mph (56.33 km/h) | 36.2 mph (58.25 km/h) |
| 40 mph (64.37 km/h) | 41.37 mph (66.58 km/h) |
| 45 mph (72.42 km/h) | 46.54 mph (74.9 km/h) |
| 50 mph (80.47 km/h) | 51.71 mph (83.22 km/h) |
| 55 mph (88.51 km/h) | 56.88 mph (91.54 km/h) |
| 60 mph (96.56 km/h) | 62.05 mph (99.86 km/h) |
| 65 mph (104.61 km/h) | 67.22 mph (108.19 km/h) |
| 70 mph (112.65 km/h) | 72.4 mph (116.51 km/h) |
| 75 mph (120.7 km/h) | 77.57 mph (124.83 km/h) |
| 80 mph (128.75 km/h) | 82.74 mph (133.15 km/h) |
| 85 mph (136.79 km/h) | 87.91 mph (141.48 km/h) |
| 90 mph (144.84 km/h) | 93.08 mph (149.8 km/h) |
| 95 mph (152.89 km/h) | 98.25 mph (158.12 km/h) |
| 100 mph (160.93 km/h) | 103.42 mph (166.44 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1797 | 2088 | 2248 | 2348 | 2455 | 2531 | 2615 | 2715 | 2852 | 2990 | 3143 | 3265 | 3487 | 3732 | 3923 | 4045 | 4114 | 4367 | 4718 | 5483 |
Better Fuel Economy Factory Ratios Increased Power
