Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 255/70-18 | 305/55-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 32.06 (814.2) | 33.21 (843.5) | 1.15 (29.3) 3.6% |
| Width inches (mm) | 10.04 (255) | 12.01 (305) | 1.97 (50) 19.6% |
| Circum. inches (mm) | 100.7 (2557.88) | 104.33 (2649.93) | 3.62 (92.05) 3.6% |
| Sidewall Height inches (mm) | 7.03 (178.5) | 6.6 (167.75) | -0.42 (-10.75) -6% |
| Revolutions per mile (km) | 629.17 (390.95) | 607.31 (377.37) | -21.85 (-13.58) -3.5% |
305/55-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.72 mph (33.35 km/h) |
| 25 mph (40.23 km/h) | 25.9 mph (41.68 km/h) |
| 30 mph (48.28 km/h) | 31.08 mph (50.02 km/h) |
| 35 mph (56.33 km/h) | 36.26 mph (58.35 km/h) |
| 40 mph (64.37 km/h) | 41.44 mph (66.69 km/h) |
| 45 mph (72.42 km/h) | 46.62 mph (75.03 km/h) |
| 50 mph (80.47 km/h) | 51.8 mph (83.36 km/h) |
| 55 mph (88.51 km/h) | 56.98 mph (91.7 km/h) |
| 60 mph (96.56 km/h) | 62.16 mph (100.04 km/h) |
| 65 mph (104.61 km/h) | 67.34 mph (108.37 km/h) |
| 70 mph (112.65 km/h) | 72.52 mph (116.71 km/h) |
| 75 mph (120.7 km/h) | 77.7 mph (125.04 km/h) |
| 80 mph (128.75 km/h) | 82.88 mph (133.38 km/h) |
| 85 mph (136.79 km/h) | 88.06 mph (141.72 km/h) |
| 90 mph (144.84 km/h) | 93.24 mph (150.05 km/h) |
| 95 mph (152.89 km/h) | 98.42 mph (158.39 km/h) |
| 100 mph (160.93 km/h) | 103.6 mph (166.73 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1546 | 1795 | 1934 | 2019 | 2111 | 2177 | 2249 | 2335 | 2453 | 2571 | 2703 | 2808 | 2999 | 3209 | 3374 | 3479 | 3538 | 3755 | 4058 | 4715 |
Better Fuel Economy Factory Ratios Increased Power
