Q: What is ethanol?
A: Ethanol is an ethyl alcohol or grain alcohol. The common method of making ethanol today is to ferment corn and add gasoline, making it unfit for human consumption. One bushel of corn produces 2.5 gallons of ethanol. Like biodiesel, ethanol is commonly blended with petroleum gasoline. The most common blends are E10 (10% ethanol and 90% gasoline) and E85 (85% ethanol and 15% gasoline).
Q: How does ethanol benefit the environment?
A: All vehicles release two types of emissions: exhaust and evaporative. Ethanol blended fuels have lower carbon and hydrocarbon exhaust emissions than petroleum gasoline. Unlike gasoline, ethanol contains oxygen, making it a cleaner burning fuel and reducing air toxins.
Ethanol also has fewer evaporative emissions. Evaporative emissions arise from a build-up of heat in the fuel tank that causes parts of the fuel to boil off and leak in the air. Ethanol has a lower vapor pressure than gasoline and does not boil as easily, creating fewer emissions.
Q: Can I use ethanol in the vehicle I have now?
A: Yes, in fact you are probably using it now and do not realize it. All automakers approve the use of E10 in their vehicles. E10 can also be used in small engines, such as boats and lawnmowers, without modification. Today ethanol is blended in 70% of America’s gasoline.
If you want to use E85 you will need to have a Flex Fuel Vehicle (FFV). FFV’s have changes in the fuel management system and a special engine calibration that accommodate the physical properties of ethanol. FFV's can run on either E85 or petroleum gasoline.
Q: How is ethanol different from MTBE?
A: MTBE (methyl tertiary butyl ether) is a gasoline additive used to oxygenate gasoline. MTBE contains toxic substances and has been banned in more than 25 states. Ethanol also oxygenates gasoline but it does not contain the toxic substances found in MTBE.
Q: How will ethanol affect the performance of my vehicle?
A: E10 blended with gasoline raises the octane number of the gasoline. Octane is a measure of the resistance of the fuel to self-igniting. A higher octane number gives the fuel more resistance to self-igniting, increasing the efficiency of the engine.
Ethanol contains 27% less energy than gasoline so if using E85 you may see a decrease in fuel economy. If using E10, very little effect on fuel economy can be detected.
Q: Does the production of ethanol have a negative net energy balance?
A: No. As of the latest USDA report, ethanol from corn creates 70% (2.3 BTU produced to 1 BTU input) more energy than the actual production process uses.