Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 305/40-23 | 420/70-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 32.61 (828.2) | 43.15 (1096) | 10.54 (267.8) 32.3% |
| Width inches (mm) | 12.01 (305) | 16.54 (420) | 4.53 (115) 37.7% |
| Circum. inches (mm) | 102.44 (2601.87) | 135.56 (3443.19) | 33.12 (841.32) 32.3% |
| Sidewall Height inches (mm) | 4.8 (122) | 11.57 (294) | 6.77 (172) 141% |
| Revolutions per mile (km) | 618.53 (384.34) | 467.4 (290.43) | -151.13 (-93.91) -24.4% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 26.47 mph (42.59 km/h) |
| 25 mph (40.23 km/h) | 33.08 mph (53.24 km/h) |
| 30 mph (48.28 km/h) | 39.7 mph (63.89 km/h) |
| 35 mph (56.33 km/h) | 46.32 mph (74.54 km/h) |
| 40 mph (64.37 km/h) | 52.93 mph (85.19 km/h) |
| 45 mph (72.42 km/h) | 59.55 mph (95.84 km/h) |
| 50 mph (80.47 km/h) | 66.17 mph (106.49 km/h) |
| 55 mph (88.51 km/h) | 72.78 mph (117.14 km/h) |
| 60 mph (96.56 km/h) | 79.4 mph (127.78 km/h) |
| 65 mph (104.61 km/h) | 86.02 mph (138.43 km/h) |
| 70 mph (112.65 km/h) | 92.63 mph (149.08 km/h) |
| 75 mph (120.7 km/h) | 99.25 mph (159.73 km/h) |
| 80 mph (128.75 km/h) | 105.87 mph (170.38 km/h) |
| 85 mph (136.79 km/h) | 112.48 mph (181.03 km/h) |
| 90 mph (144.84 km/h) | 119.1 mph (191.68 km/h) |
| 95 mph (152.89 km/h) | 125.72 mph (202.32 km/h) |
| 100 mph (160.93 km/h) | 132.34 mph (212.97 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1189 | 1382 | 1488 | 1554 | 1625 | 1675 | 1731 | 1797 | 1888 | 1979 | 2080 | 2161 | 2308 | 2470 | 2597 | 2678 | 2723 | 2890 | 3123 | 3629 |
Better Fuel Economy Factory Ratios Increased Power
