Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/40-18 | 305/50-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.24 (717.2) | 32.01 (813) | 3.77 (95.8) 13.4% |
| Width inches (mm) | 12.8 (325) | 12.01 (305) | -0.79 (-20) -6.2% |
| Circum. inches (mm) | 88.71 (2253.15) | 100.56 (2554.11) | 11.85 (300.96) 13.4% |
| Sidewall Height inches (mm) | 5.12 (130) | 6 (152.5) | 0.89 (22.5) 17.3% |
| Revolutions per mile (km) | 714.26 (443.82) | 630.1 (391.52) | -84.17 (-52.3) -11.8% |
305/50-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 22.67 mph (36.49 km/h) |
| 25 mph (40.23 km/h) | 28.34 mph (45.61 km/h) |
| 30 mph (48.28 km/h) | 34.01 mph (54.73 km/h) |
| 35 mph (56.33 km/h) | 39.68 mph (63.85 km/h) |
| 40 mph (64.37 km/h) | 45.34 mph (72.97 km/h) |
| 45 mph (72.42 km/h) | 51.01 mph (82.09 km/h) |
| 50 mph (80.47 km/h) | 56.68 mph (91.22 km/h) |
| 55 mph (88.51 km/h) | 62.35 mph (100.34 km/h) |
| 60 mph (96.56 km/h) | 68.01 mph (109.46 km/h) |
| 65 mph (104.61 km/h) | 73.68 mph (118.58 km/h) |
| 70 mph (112.65 km/h) | 79.35 mph (127.7 km/h) |
| 75 mph (120.7 km/h) | 85.02 mph (136.82 km/h) |
| 80 mph (128.75 km/h) | 90.69 mph (145.95 km/h) |
| 85 mph (136.79 km/h) | 96.35 mph (155.07 km/h) |
| 90 mph (144.84 km/h) | 102.02 mph (164.19 km/h) |
| 95 mph (152.89 km/h) | 107.69 mph (173.31 km/h) |
| 100 mph (160.93 km/h) | 113.36 mph (182.43 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1603 | 1863 | 2006 | 2095 | 2190 | 2259 | 2334 | 2422 | 2545 | 2668 | 2804 | 2914 | 3111 | 3330 | 3500 | 3610 | 3671 | 3896 | 4210 | 4892 |
Better Fuel Economy Factory Ratios Increased Power
