Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 305/40-23 | 420/65-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 32.61 (828.2) | 41.5 (1054) | 8.89 (225.8) 27.3% |
| Width inches (mm) | 12.01 (305) | 16.54 (420) | 4.53 (115) 37.7% |
| Circum. inches (mm) | 102.44 (2601.87) | 130.36 (3311.24) | 27.93 (709.37) 27.3% |
| Sidewall Height inches (mm) | 4.8 (122) | 10.75 (273) | 5.94 (151) 123.8% |
| Revolutions per mile (km) | 618.53 (384.34) | 486.02 (302) | -132.51 (-82.34) -21.4% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 25.45 mph (40.96 km/h) |
| 25 mph (40.23 km/h) | 31.82 mph (51.2 km/h) |
| 30 mph (48.28 km/h) | 38.18 mph (61.44 km/h) |
| 35 mph (56.33 km/h) | 44.54 mph (71.68 km/h) |
| 40 mph (64.37 km/h) | 50.91 mph (81.92 km/h) |
| 45 mph (72.42 km/h) | 57.27 mph (92.17 km/h) |
| 50 mph (80.47 km/h) | 63.63 mph (102.41 km/h) |
| 55 mph (88.51 km/h) | 70 mph (112.65 km/h) |
| 60 mph (96.56 km/h) | 76.36 mph (122.89 km/h) |
| 65 mph (104.61 km/h) | 82.72 mph (133.13 km/h) |
| 70 mph (112.65 km/h) | 89.08 mph (143.37 km/h) |
| 75 mph (120.7 km/h) | 95.45 mph (153.61 km/h) |
| 80 mph (128.75 km/h) | 101.81 mph (163.85 km/h) |
| 85 mph (136.79 km/h) | 108.17 mph (174.09 km/h) |
| 90 mph (144.84 km/h) | 114.54 mph (184.33 km/h) |
| 95 mph (152.89 km/h) | 120.9 mph (194.57 km/h) |
| 100 mph (160.93 km/h) | 127.26 mph (204.81 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1237 | 1437 | 1547 | 1616 | 1689 | 1742 | 1800 | 1868 | 1963 | 2058 | 2163 | 2247 | 2400 | 2568 | 2700 | 2784 | 2832 | 3005 | 3247 | 3774 |
Better Fuel Economy Factory Ratios Increased Power
