Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 175/90-18 | 305/55-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 30.4 (772.2) | 33.21 (843.5) | 2.81 (71.3) 9.2% |
| Width inches (mm) | 6.89 (175) | 12.01 (305) | 5.12 (130) 74.3% |
| Circum. inches (mm) | 95.51 (2425.94) | 104.33 (2649.93) | 8.82 (224) 9.2% |
| Sidewall Height inches (mm) | 6.2 (157.5) | 6.6 (167.75) | 0.4 (10.25) 6.5% |
| Revolutions per mile (km) | 663.39 (412.21) | 607.31 (377.37) | -56.08 (-34.84) -8.5% |
305/55-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.85 mph (35.16 km/h) |
| 25 mph (40.23 km/h) | 27.31 mph (43.95 km/h) |
| 30 mph (48.28 km/h) | 32.77 mph (52.74 km/h) |
| 35 mph (56.33 km/h) | 38.23 mph (61.53 km/h) |
| 40 mph (64.37 km/h) | 43.69 mph (70.32 km/h) |
| 45 mph (72.42 km/h) | 49.16 mph (79.11 km/h) |
| 50 mph (80.47 km/h) | 54.62 mph (87.9 km/h) |
| 55 mph (88.51 km/h) | 60.08 mph (96.69 km/h) |
| 60 mph (96.56 km/h) | 65.54 mph (105.48 km/h) |
| 65 mph (104.61 km/h) | 71 mph (114.27 km/h) |
| 70 mph (112.65 km/h) | 76.46 mph (123.06 km/h) |
| 75 mph (120.7 km/h) | 81.93 mph (131.85 km/h) |
| 80 mph (128.75 km/h) | 87.39 mph (140.64 km/h) |
| 85 mph (136.79 km/h) | 92.85 mph (149.43 km/h) |
| 90 mph (144.84 km/h) | 98.31 mph (158.21 km/h) |
| 95 mph (152.89 km/h) | 103.77 mph (167 km/h) |
| 100 mph (160.93 km/h) | 109.23 mph (175.79 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
