E10 gasoline and the outboard motor

Since October 2019, gas stations in the Netherlands are often required to sell E10 gasoline as euro 95. This gasoline contains up to 10% of bioethanol. This affects your outboard motor.

What is it?

Virtually everyone is concerned with climate change, especially legislators. It has determined that more bioethanol must be added to gasoline to reduce greenhouse gas emissions. E10 gasoline contains 90% regular euro 95 and 10% bio ethanol.

Some facts about ethanol

• Ethanol has a lower energy density than gasoline. There is about 30% less energy in a liter of pure ethanol than in a liter of gasoline.
• E10 gasoline provides slightly higher fuel economy, normally a few percent.
• Bio ethanol is produced from corn, sugar cane, soybeans and other organic matter.
• Ethanol is hygroscopic, which means it attracts water.

Gasoline shelf life

Euro 95 gasoline or E10 has a limited shelf life. This is due to a number of reasons;

• Oxidation of the individual components of the fuel. Gasoline consists of many chemicals, which can react with oxygen. This eventually causes old gasoline to deteriorate.
• Moisture in gasoline: this has been a bigger problem since the advent of E10. Because ethanol attracts water, more moisture enters the gasoline. When this becomes too much it sinks to the bottom of the tank, where the engine intake is also located.

How long gasoline keeps depends on several factors, including temperature and outdoor exposure. Under poor conditions, gasoline can deteriorate in quality after only a few weeks. However, an unequivocal answer is difficult to give. What is certain is that E10 has more adverse properties than E5.

Moisture in the fuel

Once moisture is in the gasoline, it can cause problems. Of course, water does not burn, so this causes a direct problem. But in addition, indirect problems can occur by damaging parts. Steel tanks can rust, and engine parts will also wear harder from contact with water.

Vergomming

Gilding from E10 gasoline is a common complaint, but according to reputable fuel manufacturers, this is a problem not related to E10 but could always take place.

Which outboard engines are suitable for E10 gasoline?

As an owner of an outboard motor, you are naturally curious to know if your motor can use E10, or if you should look for more expensive E5. We have listed here which engines are suitable for E10.

• All Yamaha outboard engines from after 2003 are suitable for E10
• All Mercury/Mariner engines from after 1996 are suitable for E10
• All Suzuki 4-stroke models are suitable for E10. Older Suzuki two-stroke models are not suitable for E10.
• All Honda engines sold in the EU since 1996 are suitable for E10.
• All Evinrude E-Tec engines are suitable for E10.
• All Tohatsu engines are suitable for E10.

Tips for conserving fuel

Many boats are not used much, if at all, during the winter. This can cause problems with gasoline storage. To get this right, here are some tips.

• Solid tanks are best filled completely for storage. This means there is less air in the tank and there will be less condensation and deterioration of gasoline.
• Loose tanks are best removed from the boat, and stored empty. After the winter, you can fill them with clean gasoline.
• When you do store a loose tank filled, make sure it is completely full and that the vent is closed. Store in a cool place.