Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 305/40-20 | 305/45-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 29.61 (752) | 30.81 (782.5) | 1.2 (30.5) 4.1% |
| Width inches (mm) | 12.01 (305) | 12.01 (305) | 0 (0) 0% |
| Circum. inches (mm) | 93.01 (2362.48) | 96.78 (2458.3) | 3.77 (95.82) 4.1% |
| Sidewall Height inches (mm) | 4.8 (122) | 5.4 (137.25) | 0.6 (15.25) 12.5% |
| Revolutions per mile (km) | 681.21 (423.28) | 654.66 (406.79) | -26.55 (-16.5) -3.9% |
305/45-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.81 mph (33.49 km/h) |
| 25 mph (40.23 km/h) | 26.01 mph (41.87 km/h) |
| 30 mph (48.28 km/h) | 31.22 mph (50.24 km/h) |
| 35 mph (56.33 km/h) | 36.42 mph (58.61 km/h) |
| 40 mph (64.37 km/h) | 41.62 mph (66.98 km/h) |
| 45 mph (72.42 km/h) | 46.83 mph (75.36 km/h) |
| 50 mph (80.47 km/h) | 52.03 mph (83.73 km/h) |
| 55 mph (88.51 km/h) | 57.23 mph (92.1 km/h) |
| 60 mph (96.56 km/h) | 62.43 mph (100.48 km/h) |
| 65 mph (104.61 km/h) | 67.64 mph (108.85 km/h) |
| 70 mph (112.65 km/h) | 72.84 mph (117.22 km/h) |
| 75 mph (120.7 km/h) | 78.04 mph (125.6 km/h) |
| 80 mph (128.75 km/h) | 83.24 mph (133.97 km/h) |
| 85 mph (136.79 km/h) | 88.45 mph (142.34 km/h) |
| 90 mph (144.84 km/h) | 93.65 mph (150.72 km/h) |
| 95 mph (152.89 km/h) | 98.85 mph (159.09 km/h) |
| 100 mph (160.93 km/h) | 104.06 mph (167.46 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1666 | 1935 | 2084 | 2176 | 2276 | 2347 | 2425 | 2517 | 2644 | 2772 | 2914 | 3027 | 3233 | 3460 | 3637 | 3750 | 3814 | 4048 | 4374 | 5083 |
Better Fuel Economy Factory Ratios Increased Power
