Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 210/40-18 | 120/70-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 24.61 (625.2) | 27.61 (701.4) | 3 (76.2) 12.2% |
| Width inches (mm) | 8.27 (210) | 4.72 (120) | -3.54 (-90) -42.9% |
| Circum. inches (mm) | 77.33 (1964.12) | 86.75 (2203.51) | 9.42 (239.39) 12.2% |
| Sidewall Height inches (mm) | 3.31 (84) | 3.31 (84) | -0 (-0) -0% |
| Revolutions per mile (km) | 819.37 (509.13) | 730.35 (453.82) | -89.02 (-55.31) -10.9% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 22.44 mph (36.11 km/h) |
| 25 mph (40.23 km/h) | 28.05 mph (45.14 km/h) |
| 30 mph (48.28 km/h) | 33.66 mph (54.16 km/h) |
| 35 mph (56.33 km/h) | 39.27 mph (63.19 km/h) |
| 40 mph (64.37 km/h) | 44.88 mph (72.22 km/h) |
| 45 mph (72.42 km/h) | 50.48 mph (81.25 km/h) |
| 50 mph (80.47 km/h) | 56.09 mph (90.27 km/h) |
| 55 mph (88.51 km/h) | 61.7 mph (99.3 km/h) |
| 60 mph (96.56 km/h) | 67.31 mph (108.33 km/h) |
| 65 mph (104.61 km/h) | 72.92 mph (117.36 km/h) |
| 70 mph (112.65 km/h) | 78.53 mph (126.38 km/h) |
| 75 mph (120.7 km/h) | 84.14 mph (135.41 km/h) |
| 80 mph (128.75 km/h) | 89.75 mph (144.44 km/h) |
| 85 mph (136.79 km/h) | 95.36 mph (153.47 km/h) |
| 90 mph (144.84 km/h) | 100.97 mph (162.49 km/h) |
| 95 mph (152.89 km/h) | 106.58 mph (171.52 km/h) |
| 100 mph (160.93 km/h) | 112.19 mph (180.55 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1859 | 2159 | 2325 | 2428 | 2539 | 2618 | 2705 | 2808 | 2950 | 3092 | 3251 | 3377 | 3606 | 3860 | 4057 | 4184 | 4255 | 4516 | 4880 | 5671 |
Better Fuel Economy Factory Ratios Increased Power
