Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 425/85-21 | 400/70-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 49.44 (1255.9) | 43.05 (1093.4) | -6.4 (-162.5) -12.9% |
| Width inches (mm) | 16.73 (425) | 15.75 (400) | -0.98 (-25) -5.9% |
| Circum. inches (mm) | 155.34 (3945.53) | 135.24 (3435.02) | -20.1 (-510.51) -12.9% |
| Sidewall Height inches (mm) | 14.22 (361.25) | 11.02 (280) | -3.2 (-81.25) -22.5% |
| Revolutions per mile (km) | 407.89 (253.45) | 468.51 (291.12) | 60.62 (37.67) 14.9% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 17.41 mph (28.02 km/h) |
| 25 mph (40.23 km/h) | 21.77 mph (35.03 km/h) |
| 30 mph (48.28 km/h) | 26.12 mph (42.03 km/h) |
| 35 mph (56.33 km/h) | 30.47 mph (49.04 km/h) |
| 40 mph (64.37 km/h) | 34.82 mph (56.04 km/h) |
| 45 mph (72.42 km/h) | 39.18 mph (63.05 km/h) |
| 50 mph (80.47 km/h) | 43.53 mph (70.06 km/h) |
| 55 mph (88.51 km/h) | 47.88 mph (77.06 km/h) |
| 60 mph (96.56 km/h) | 52.24 mph (84.07 km/h) |
| 65 mph (104.61 km/h) | 56.59 mph (91.07 km/h) |
| 70 mph (112.65 km/h) | 60.94 mph (98.08 km/h) |
| 75 mph (120.7 km/h) | 65.3 mph (105.08 km/h) |
| 80 mph (128.75 km/h) | 69.65 mph (112.09 km/h) |
| 85 mph (136.79 km/h) | 74 mph (119.09 km/h) |
| 90 mph (144.84 km/h) | 78.35 mph (126.1 km/h) |
| 95 mph (152.89 km/h) | 82.71 mph (133.11 km/h) |
| 100 mph (160.93 km/h) | 87.06 mph (140.11 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1192 | 1385 | 1492 | 1558 | 1629 | 1679 | 1735 | 1801 | 1892 | 1984 | 2085 | 2166 | 2314 | 2476 | 2603 | 2684 | 2730 | 2897 | 3130 | 3638 |
Better Fuel Economy Factory Ratios Increased Power
