You can probably figure out your car’s gas mileage in your head. Simply divide the number of miles driven on a full tank by the number of gallons the tank can hold to estimate the vehicle’s fuel economy. Unfortunately, it’s a different story calculating your boat’s fuel consumption. Because sea conditions vary more widely than road conditions, the time it takes to cover a distance also varies more. For this reason, boat fuel consumption is measured in gallons per hour. The pros call it “brake-specific fuel consumption,” and it is a very important consideration when shopping for a new boat or engine. Here are a few tips to help you estimate a boat’s fuel consumption.
Weights and Constants
Before you can calculate your boat’s fuel consumption, there are a few figures you need to know. First, because marine fuel efficiency is measured in pounds of fuel used per horsepower delivers per hour, you need to know that gasoline weighs about 6.1 pounds per gallon and diesel fuel weighs 7.2 pounds per gallon. You also need to know that, on average, a four-stroke gasoline engine will burn about 0.50 pounds of fuel per hour for each unit of horsepower. Likewise, a diesel engine burns about 0.40 pounds of fuel per hour for each unit of horsepower it produces.
Formula for Maximum Engine Fuel Consumption
Now that you know these constants, you can plug them into the equation for estimating maximum engine fuel consumption. To determine your boat’s gallons per hour (GPH), multiply the engine’s fuel consumption rate by the engine’s maximum horsepower and divide by the weight of the fuel used. For example, in a 300-horsepower diesel engine, the GPH would be 0.40 (the amount of fuel burned per hour for) multiplied by 300, divided by 7.2 (the weight of one gallon of diesel fuel).
If any of this is confusing to you, contact the boat experts at Moose Landing Marina in Naples, Maine. Our staff is happy to help you find the perfect new boat for you and your family. We even offer boat rentals, storage, service, and more! Visit our website to learn more about our full-service marina, or call us at (888) 379-8265 for additional information.