How to Maximize Your Boat Engine Fuel Efficiency

Fuel is one of the largest ongoing costs of boat ownership. Small improvements in efficiency add up to significant savings over a season. Here's how to get the most miles per gallon from your marine engine.

Keep Your Engine Well-Maintained

A properly tuned engine runs more efficiently:

• Fresh spark plugs: Worn plugs cause incomplete combustion
• Clean fuel filters: Restricted flow hurts performance
• Proper oil level: Too much or too little increases drag
• Clean air filter: Restricted air means rich running

Choose the Right Propeller

The wrong prop can cost you 10-20% in fuel economy:

• Correct pitch: Engine should reach WOT RPM range
• Material matters: Stainless props are more efficient than aluminum
• Match to use: Heavy loads need lower pitch
• Keep it perfect: Even minor damage hurts efficiency

Reduce Weight and Drag

Weight reduction:

• Remove unnecessary gear and equipment
• Don't overload on fuel (partial tanks are lighter)
• Use lighter equipment where practical

Drag reduction:

• Keep the hull clean - growth dramatically increases drag
• Properly trim the engine for conditions
• Distribute weight evenly for optimal running attitude

Find Your Efficient Cruising Speed

Most boats have a "sweet spot" where fuel efficiency peaks:

• Usually just above planing speed
• Watch your fuel flow meter if equipped
• Often 3500-4000 RPM for many four-strokes
• Running flat out burns exponentially more fuel

Trim Properly

Proper trim reduces drag significantly:

• Bow-down: Better for acceleration and rough water
• Bow-up: Better for cruising efficiency
• Adjust for changing conditions and loads
• Watch for porpoising (over-trimmed) or plowing (under-trimmed)

Plan Your Route

• Avoid running directly into heavy chop when possible
• Use current and wind to your advantage
• Take the most direct route when conditions allow
• Avoid excessive idling

Consider Engine Technology

If you're in the market for a new engine, consider:

• Four-stroke vs two-stroke: Four-strokes typically 15-30% more efficient
• EFI vs carbureted: Fuel injection improves economy
• Right-sized power: Oversized engines burn more fuel

Monitor and Track

• Use a fuel flow meter to track consumption
• Record fuel usage to spot efficiency changes
• Changes in economy can indicate maintenance needs

Looking for a more fuel-efficient engine? Browse our selection of modern four-stroke outboards known for excellent economy.