Ethanol, E85, Flex Fuel…What Does It All Mean?

man filling up car with E85 gas
How much do you know about E85? Check out these alternative fuel vehicle pictures to learn more!
General Motors

Flex Fuel? Ethanol? E85? Been wondering what exactly all of this means?

You are probably not alone.


In an effort to reduce our fossil fuel consumption, automakers and fuel companies have been looking into the addition of a product in with the gasoline that would allow vehicles to perform just as well while lowering our dependence on the petroleum product. Ethanol emerged as a renewable source of high-octane, clean-burning fuel and is derived primarily from corn products here in the U.S.

Flexible Fuel Vehicles (FFVs) are designed to run on a certain blend of the Ethanol in with unleaded gasoline with concentrations of the Ethanol as high as 85 percent, thus giving us the E85 derivative.

While most fuel contains some percentage of Ethanol these days only vehicles with the Flex Fuel designation can tolerate the E85 blend and no production vehicles run on pure Ethanol (grain alcohol).

Ethanol-based fuels are touted as being more environmentally friendly than gasoline only as carbon monoxide emissions are reduced and as it contains 35 percent oxygen it burns cleaner and more completely than gasoline.


Ethanol as a Racing Fuel

Ethanol has made its way into auto racing, first in the Indy Racing League by 2007 and this year into all three NASCAR national touring series with “Green E15” as its official race fuel. The Indy cars now burn a pure 100 percent Ethanol blend (switching over from Methanol) but will make the switch to E85 for 2012.


What About My Boat?

While all consumer vehicles and all Flex Fuel Vehicles can run on pure gasoline, not all gasoline engines can run on E85. Care must be taken when refueling your older model vehicle as this high a blend of Ethanol can damage fuel lines and other components. The same care should be taken for motorcycles, ATVs, boats and personal watercraft, lawn mowers and other yard equipment, and generators. E10 fuel, or “gasohol” (up to 10 percent Ethanol additive), is generally safe for them.


Do You Drive an FFV?

ford hybrid truck, e85
Have you ever seen a truck that runs on E85?

How do you tell if you have a Flex Fuel Vehicle? A yellow gas cap may be your first clue, or some designation inside the fuel filler door displaying the E85 alphanumeric. Vehicles running on E85 tend to experience a drop in fuel economy versus gasoline (up to 25-30%) due to Ethanol’s lower energy content but at the benefit of burning cleaner. Vehicles burning the E10 fuel blend will see a drop of about 3-4% in fuel economy over straight gasoline.

As Ethanol can be produced by fermenting and distilling any starch crop or “cellulosic biomass,” it is a promising renewable fuel source that, at least for now, will help reduce the world’s petroleum dependence.


One obstacle that stands in Ethanol’s way now is the higher fuel economy standards imposed by the current U.S. administration. As E85 is less efficient, automakers will be putting their efforts into ways to quickly increase the numbers the EPA places on those window stickers and Ethanol-rich fuel is not one of those – for now.

Ethanol and E85

e85 gas map
Where can you fill up?

Ethanol and E85 were the buzzwords a few years ago but now nearly gone from marketing presentations and press conferences. Competing with an image of a starving migrant farm worker claiming E85 fuel was making the price of tortillas skyrocket was a tough PR fight. Manufacturers, however, still include FFV powertrains in their respective lineups as the E85 infrastructure has developed in recent years thanks in part to key investments from them.

And let me leave you with a fun fact I did not know: Henry Ford’s Model T was the first commercially available flexible fuel vehicle as it ran on gasoline, ethanol, or any blend of the two.