Fuel Economy

How Ethanol Affects the Fuel Economy

For you to gain knowledge in how ethanol affects fuel economy, you first need to recognize what ethanol is. Ethanol is a renewable form of energy that is produced domestically. It is alcohol fuel that is made from plant matter which includes; grasses, corn or sugarcane. The use of ethanol and reduces the dependence on oil, and the release of greenhouse gas by a steep margin. Use of ethanol has increased drastically within the last decade. This is because it provides an excellent alternative to oil, as a fuel.

Now that you know that ethanol is an alternative biofuel, the next question that we need to address is how it affects the fuel economy.

The E10 and E15

E10 and E15 are both a blend of ethanol and gasoline. The letter E represents ethanol and the number after the letter, represents the percentage of ethanol present in the mixture, by volume. In countries like the U.S.A, most of the gasoline sold is known to contain up to ten per cent ethanol. This figure changes with the region. All companies that manufacture cars approve blends that carry a maximum of 10% ethanol in their vehicles which are powered by gasoline. To make it easier, vehicles’ owners’ manuals tend to indicate the maximum amount of ethanol that is recommended for the vehicle, by its manufacturer.

Flex fuel

This fuel is also known as E85. It is an ethanol and gasoline blend which contains about 51% to 83% of ethanol. The changes are due to geography and season. Winter blends tend to have less ethanol; on the other hand, summer blends have more ethanol. FFVs which are specially made to run on gasoline, flex fuel or any mixture of these two, can run on flex fuel. These vehicles are offered by many auto manufacturers.

Flex fuel has a lower energy content as compared to regular gasoline, which contains some ethanol. The cost of these blends of ethanol and gasoline varies and fluctuates according to the energy markets. When it comes to performance, some vehicles such as FFVs perform much better when running on flex fuel. They have more horsepower and torque.

In the U.S alone, and upward of 2,800 filling stations sell flex fuel. Anywhere else around the world, you can search for alternative fuelling stations, for ethanol blends of fuel.

Ethanol has both positive and negative effects on the fuel economy. The positives are; ethanol is produced domestically, thus reducing your dependency on oil. Ethanol fuels emit lower levels of some air pollutants as compared to oil. Fuels which are blends of ethanol provide more resistance to engine knock, and finally, the added vehicle cost when ethanol blends are used is negligible. The negatives are; ethanol infused fuels can only be used on specific vehicles, flex fuel has a lower energy content thus lowering the gasoline mileage and finally, flex fuel is not readily available in all areas.

Advantages of flex fuel

  • Domestically produced (reduces oil dependence)
  • Lower emissions of some air pollutants
  • More resistant to engine knock
  • Added vehicle cost is negligible

Disadvantages of flex fuel

  • Can only be used in flex-fuel vehicles
  • Lower energy content (lower gas mileage)
  • Limited availability