Fueling Your Boat 101

When it comes to fuel for your boat, it’s not quite as simple as filling up your car’s tank. To help you get the info and confidence you need when deciding on a boat and what kind of fuel it will use, and how to boost efficiency while you’re out on the water, check out these tips and guidelines.

Types of Fuel

Boats run on either diesel or gasoline engines. Smaller inboard or stern-drive powerboats up to about 30 to 35-feet usually only have gas engines. The range between 35 and 45 feet use both diesel and gasoline, but beyond about 45 feet, you’ll only have one choice, and that will be diesel. Pro and con discussions can go pretty deep, but in general, diesel fuel has about 10 percent more energy potential per gallon than gasoline, and diesel engines are more efficient than gasoline engines. While gasoline, on average, can cost less, keep in mind that diesel engines tend to be a little louder. So, depending on how you feel about cost savings and noise reduction, you’ll need to weigh your options.

Fuel-Saving Tips

Choose the right prop. The right prop can help your engine run as efficiently as possible. Replacing the stock “all-round” prop with one specifically designed to give better fuel economy can make a big difference in your annual fuel bill.

Burn less fuel. This one’s pretty basic: If you can slow down and maintain a consistent cruising speed, you’ll use less gas.

Reduce wind resistance. If your boat has a Bimini top, it can cause a lot of extra drag which affects fuel efficiency. Once you’re under way, drop the top, and make sure your windshield and other enclosures are closed to lessen wind resistance.

Weight distribution. Always try to distribute passengers and gear so that your boat can easily get up on plane, and doesn’t just plow through the water. Getting rid of excess weight on the boat will help too, so store cleaning supplies, old hardware, tools and unneeded tackle in a locker on shore, don’t take it with you.

Clean your hull. Algae, zebra mussels, barnacles and growths on the bottom of your boat can increase drag and reduce fuel efficiency.

Care for Your Fuel System

Fuel up safely. Keep the nozzle in contact with the edge of the tank opening to prevent static buildup that can cause sparking. And as they say at the coffee shop, “leave a little room” — fill your tank about 90 percent because fuel expands as temperatures rise. By cleaning up fuel spills immediately, you’ll make your boat safer (and smell better, too).

Prevent contamination. Fuel contamination can cause poor performance and may damage your engine. Indicators that your engine may have been contaminated is excessive smoke, lack of power, hesitation in acceleration or stalling. Water is the most common contaminant found in your boat fuel. It can sneak into your fuel simply through condensation in your tank. Avoid condensation by filling up before you put the boat is in storage. Occasionally, adding a simple “dry gas” additive when fueling your boat during the season is a good idea.

Fuel maintenance. Near the end of the boating season, you should add a fuel stabilizer and run your engine long enough to draw the enhanced fuel into the engine. This will keep the fuel from breaking down over time and gumming up your carburetor or fuel injectors. Inspect your fuel filters annually — lay-up time is a good time for this.

Learning as much as you can about the fuel you use will make you a more informed boater so you can avoid extra maintenance costs throughout the season and keep your boat running great longer.