E85 gas (also known as flex fuel) is a high-level combination of ethanol and gasoline that consists of 51 percent to 83 percent ethanol blended with gasoline. The percentage of ethanol depends on the geographical location and time of the year. Producers add more ethanol in the summer as opposed to the winter.
E85 (Flex Fuel)
E85 is the most common form of flex fuel available on the market. Because ethanol is corn-based, E85 gas is readily available in the Midwest region of the United States. It's less available in other regions, especially New England and the Pacific Northwest. According to the U.S. Department of Energy, there are 3300 E85 gas stations available to the public across 42 states. Outside the United States, ethanol producers often use alternative crops. In Brazil, sugar cane is a prominent source of ethanol.
Research by the U.S. Energy Information Administration shows that pure ethanol has a lower heating value than gasoline, so it makes it harder to start a car's engine in areas with a cold climate. This difficulty in cold cranking is why ethanol blends contain a fraction of gasoline. E85 gas is suitable for use in any vehicle designated as a flex-fuel vehicle by the manufacturer. Cars.com reports that flex-fuel vehicles are capable of running on both ethanol-gasoline blends and regular gasoline. Consumers can use the Department of Energy's vehicle cost calculator to determine how much a flex-fuel vehicle can save on fuel costs and greenhouse gas emissions.
Because of Brazil's relatively warmer climate, gas stations in that country can sell pure ethanol. Flex-fuel vehicles in Brazil run on E100 as opposed to the E85 that is for sale in most parts of the world. Fuel sold as E100 is always 100 percent ethanol, while fuel sold as E85 always contains 85 percent ethanol. Using a guaranteed fraction of ethanol makes it easier for a vehicle to reach peak performance and fuel economy.
In Austalia, E85 is the preferred fuel among motor racing clubs and sports car enthusiasts. The motor racing industry has always preferred ethanol- or methanol-based fuels because these fuels tend to give performance vehicles more thermal efficiency and increased torque. In an advanced engine, E85 can improve the engine's fuel consumption.
In the United States, the government has tried to encourage the production and sale of E85 by providing subsidies, particularly to corn producers in the Midwest. In 2016, the installation of new ethanol infrastructure began in 20 states, thanks to a $210 million grant from the U.S. Department of Agriculture. This new infrastructure will make E15 and E85 more readily available across the country.
When fueling their flex-fuel vehicles with E85 instead of regular gasoline, drivers won't notice many differences other than a decrease in miles per gallon. Compared to gasoline, ethanol provides less energy per gallon, meaning that the higher the percentage of ethanol, the more significant the impact on fuel economy.
Depending on the driver's location and the ups and downs of the energy markets, the cost of E85 can vary greatly, especially when compared to regular gasoline and E10. While E85 gas costs less than regular gasoline at the pump, the decrease in miles per gallon makes it more expensive when driving. Despite the lower miles per gallon, flex-fuel vehicles often put out more torque and more horsepower when running on E85 instead of regular gasoline.
Like all consumer products, there are pros and cons to using E85. The pros include:
- Less dependence on foreign oil
- Fewer air pollutants released into the atmosphere
- Higher resistance to engine knocking
Disadvantages to keep in mind include:
- Limited to use in flex-fuel vehicles
- Less energy per gallon, leading to fewer miles per gallon
- Not readily available in some regions
Ethanol
Ethanol is an alcohol fuel derived from several different plant materials, including corn, sugar cane, or various grasses. It is a renewable resource that is produced domestically rather than imported. The U.S. Department of Energy reports that the use of ethanol can lead to less dependence on oil and a reduction in greenhouse gases released into the atmosphere. Along with E85, other blends of ethanol and gasoline include E10 and E15. The number informs consumers of the percentage of ethanol contained in the blend.
Regular gasoline sold in the U.S. usually contains up to 10 percent ethanol. A federal mandate limits the amount of 100-percent gasoline on the market. When drivers use E10 or E15 instead of pure gasoline, they will notice a decrease in miles per gallon. This is because compared to pure gasoline, ethanol has about one-third less energy. A 10-percent blend is not a flex fuel. The Renewable Fuels Association defines a flex fuel as a blend of ethanol and gasoline that contains more than 15 percent ethanol and less than 83 percent ethanol.
According to Cars.com, flex-fuel vehicles are capable of running on flex fuel thanks to specially adapted components and revised engine software. They can run on anything from 100-percent gasoline to blends containing 85 percent ethanol. All 2001-model standard vehicles and newer can run on E15 but can't handle the corrosiveness of higher ethanol percentages.
Fuel Economy
The Society of Automotive Engineers and other supporters of E85 usage argue that if automotive manufacturers would recognize and take advantage of ethanol-based fuel's superior traits, they could make an ethanol engine that was as efficient as one powered by gasoline. According to these proponents, an ethanol engine that can reach up to 22 percent more miles per gallon than a gasoline engine already exists. It's wrong, they say, to base ethanol engine design on that of a gas engine when ethanol is closer to diesel fuel.
Critics of E85 and ethanol, in general, argue that its lower heating value outweighs any benefits. Supporters counter that argument by pointing out that heating value does not factor into overall efficiency. Adding a fraction of gasoline to ethanol blends can counteract the low heating value. E85 also has higher octane content, which can provide more engine power.
Thanks to an abundance of corn, E85 is only going to become more common in the United States. Increased support and government subsidies mean that E85 and other flex fuels are here to stay.
Information and research in this article verified by ASE-certified Master Technician Duane Sayaloune of YourMechanic.com. For any feedback or correction requests please contact us at research@caranddriver.com.
Sources:
https://afdc.energy.gov/fuels/ethanol_e85.html
https://www.eia.gov/todayinenergy/detail.php?id=18551
https://www.cars.com/articles/what-is-a-flex-fuel-vehicle-410045/
https://www.caranddriver.com/features/a15122210/ethanol-injection-systems-explained-tech-dept/
https://www.fueleconomy.gov/feg/ethanol.shtml
https://www.caranddriver.com/features/a15145172/ethanol-promises/
https://www.sae.org/publications/technical-papers/content/2002-01-2743/
