On December 19, 2019, the Environmental Protection Agency (EPA) finalized a rule allowing E15 blended gasoline be sold year-round. Previous standards set by the EPA in 2007 sought to encourage the production and use of ethanol-blended fuels, but limited E15 to be sold during “winter months” while E10 could be sold year-round.
What are E10 and E15 Fuel?
These are fuel blends containing a percentage of renewable biofuel—ethanol. E15 is a blend of 85% gasoline and 15% ethanol. And you guessed it; E10 is 90% gasoline and 10% ethanol.
Ethanol is added to gasoline primarily because of its renewable nature. Ethanol is produced from feedstock crops—often corn is used. This not only helps us be less dependent on traditional fossil fuel sources, but it brings work and money to rural America.
What is the focus on E15 biofuel?
Different blends of gasoline create different vapor pressures when burned, measured as the Reid vapor pressure (RVP). The higher the RVP, the more easily it evaporates into the air. In short, that means fuels burned with a higher RVP put more exhaust into the atmosphere.
You might assume that using more biofuel like ethanol would be better for our environment, but that’s not necessarily the case.
While pure ethanol has an RVP of only 2 psi, mixing it with gasoline raises the overall average or resulting RVP of the new blended fuel’s RVP. The more ethanol a blend has, the higher the RVP, and the more easily vapor from burning evaporates into the air.
- E15 Fuel = more ethanol = higher RVP = evaporates more easily = higher CO2 emissions
- E10 Fuel = less ethanol = lower RVP = evaporates less easily = fewer CO2 emissions
In the past, the EPA has felt that E10 was an ideal level to optimize the use of renewable resources while keeping our air clean. However, because of how engines are constructed, having a higher amount of ethanol helps engines start and run better during cold months (because of that whole “easy to evaporate” factor.) As a result, the EPA allowed E15 to be sold during the colder “winter months” while kept the blend restricted to E10 during the remaining months.
What’s the controversy?
There are a number of reasons people have questioned the EPA’s restriction of E15. First, it’s very expensive for gas station owners to switch from one blend of fuel to the next. For some, it’s cost-prohibitive to offer E15 during a few months of the year. Secondly, farmers in agricultural regions of the United States would like to see an increase in ethanol demand that using a higher percentage blend year-round would bring. According to EPA Region 7 Administrator, Jim Gulliford:
“Biofuels are a vital component to value-added agriculture here in the Midwest. In Region 7’s four states alone, we have over 100 permitted biofuel plants with Iowa and Nebraska leading our nation in ethanol production. These facilities significantly enhance markets for crops and provide great jobs in rural communities producing renewable fuel for America. Given these important contributions, I am pleased that we’re finalizing these changes to our fuel regulations.”
Others are very opposed to these changes. According to Robert Rapier, Senior Contributor to Forbes, some people continue to be concerned about the impact higher blend fuels have on our air quality. Additionally, many fear increased crop growth will create higher levels of fertilizer chemicals in water runoff to lakes and rivers.
How does this impact you?
While most vehicles manufactured after 1986 can use E10 blends of fuel, not all can use E15. In fact, the American Coalition for Ethanol has published information indicating that E15 may be used in most cars manufactured in 2001 and later. While this covers an estimated 90% of cars on the road today, if your vehicle is one of the 10% that is older than 2001, you should contact your vehicle’s manufacturer before using E15.
Want to learn more about biofuels and other forms of alternative energy?
The Rogue Valley Clean Cities Coalition’s mission is enhancing the livability of the Rogue Valley. We promote and educate on alternate fuels, seek to decrease dependency on petroleum, and promote clean air and water in the Rogue Valley via alternate fuels. Contact us today for more information!