Here is some fuel burn info on the 464.
Speed: 5.2 to 6.8 knots
Fuel burn: As low as 4.3 liters per hour (about 1.1 gallons per hour)
Range: Up to 1,785 nautical miles at 5.2 knots
At efficient cruising speeds (3,000 RPM):
Speed: 16–17 knots
Fuel burn: About 20–22.5 gallons per hour
Range: Approximately 329–400 nautical miles, depending on load and conditions
At wide-open throttle (top speed):
Speed: Up to 22.4 knots
Fuel burn: About 38.6 gallons per hour
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