The mythical E10 mandate

Many people misunderstand what the country in general — and their state in particular — is required to do about ethanol in auto gasoline. First, let’s look at the BIG picture: There is no federal mandatory E10 law. Many people believe that there is, but it is not true.

There are only six states with active mandatory ethanol laws and only five of those have mandatory E10 laws. The five states with active mandatory E10 laws are, in order of implementation: Minnesota, Hawaii, Missouri, Oregon, and Florida. The state of Washington has a wimpy mandatory 2% volumetric ethanol law. Two states have mandatory E10 laws on the books that have never triggered, and probably never will, Montana and Pennsylvania, and one other state has one of those useless 2% volumetric laws on its books that has never triggered, Louisiana.

The state of Washington is trying to repeal its mandatory volumetric law because it is now ineffectual, and Hawaii’s mandatory E10 law has been a disaster for its marine industry so officials have made changes to the law to protect the state’s marine industry and there has been an effort to completely repeal it. Missouri has also tried to repeal its mandatory E10 law.

Let’s talk about “Oxygenate Programs” since this promotes a lot of confusion about ethanol, especially ethanol blending levels. There are a number of areas in the country — they are all large metropolitan areas — that have “oxygenate” requirements in the winter. The oxygenate program is overseen by the EPA. Many of these programs have been rescinded because modern, computer controlled pollution systems in cars have vastly improved tail pipe emissions and the production of Reformulated Gasoline, commonly known as RFG, has produced a much cleaner burning fuel, vastly reducing tail pipe air pollution emissions.

The gasoline producers made an oxygenate called MTBE, which increased octane and provided excess oxygen which helps reduce CO emissions, the main pollution in winter that the EPA was trying to reduce to improve air quality. As many of you know, MTBE was an ecological disaster when it started showing up in drinking water. Turns out it was a long lived carcinogen that was absorbed in lakes and streams. So the gasoline producers, with the blessing of the EPA, turned to ethanol to replace MTBE as an oxygenate. However, the blending level for ethanol as an oxygenate to meet EPA air quality requirements is very low, less than 3.6% in all cases. To find out whether an oxygenate program is required in your state and what the blending level is, consult this EPA table. You will notice that Phoenix has the highest allowed ethanol blending from 11/02 to 3/15 of each winter season at 3.5%. You will notice that there is no requirement for E10 in any winter oxygenate program. That table also shows how many urban areas no longer have winter oxygenate programs because they no longer need them. There is no place in the U.S. that has a year round oxygenate program requirement

And finally, let’s talk about Reformulated Gasoline, or RFG. What people are confusing with oxygenate program requirements is usually an RFG requirement, also overseen by the EPA. To see if your area is in a mandatory RFG area consult this EPA table.

Many people believe that California is a mandatory E10 state. It is not, but there are many areas in California that are mandatory RFG areas, and Los Angeles County also has a winter oxygenate requirement. RFG programs are year round. In reality, 99% of all RFG produced in the nation is E10 and in California all of the gasoline producers are making E10 all the time because it is the most convenient blend to meet RFG requirements, winter oxygenate requirements and their ethanol blending quota.

So where is all of the E10 coming from? It is coming from the unintended consequences of the federal RFS mandate in a large, complicated act called the Energy Independence and Security Act (2007), a.k.a. HR-6 (2007). The website,, will explain everything you ever wanted to know about this insidious law, but suffice it to say EISA 2007 is NOT a mandatory E10 law. EISA 2007 was supposed to increase the production and distribution of E85 and sale of flex-fuel vehicles. What is ironic is that E10 is not a “Renewable Fuel” as defined by EISA 2007. Renewable Fuel is defined in several places in the act as E85 and in one place as E11 and above. E10 is gasoline made to ASTM D4814 blended with 10% ethanol, but it is still gasoline as far as the EPA and ASTM are concerned, not a Renewable Fuel. However there is a hard-coded blending quota table in the act that directs gasoline producers to blend ethanol into gasoline in ever-increasing amounts through 2022, but makes no requirement about what kind of fuel must result. You would think it would be E85, since E85 is “Renewable Fuel” but that isn’t required by the act, so we get what gasoline producers can actually sell, E10 everywhere, and by the end of next year all of the gasoline in the U.S. will have to be E10 and after that the producers will have ever-increasing ethanol blending quotas with nowhere to put it. Can you say Train Wreck?

In summary, there is no country wide mandatory E10 law, only five states have implemented mandatory E10 laws and all of those states have exceptions for marine, aircraft, old cars and small engines from the blending requirement. Then there are a few winter oxygenate areas in the country, which can be met with E3.5 or less, and finally there are RFG areas, but they require no ethanol.

So there is no reason whatsoever that the U.S. is getting E10 in all of the auto gasoline, but it’s happening nevertheless. And please understand, not one of the mandatory E10 states, which provide exceptions for aircraft use, has a statute that requires that ethanol free gasoline be produced and there is no federal statute that requires that ethanol free gasoline be produced for those applications that need it. So, as the gasoline producers are swamped by their mandatory, cast in stone, federal quotas from the table in EISA 2007, the only thing that they will make is E10 unless sanity prevails.

Dean Billing

The GAfuels Blog is written by two private pilots concerned about the future availability of fuels for piston-engine aircraft: Dean Billing, Sisters, Ore., an expert on autogas and ethanol, and Kent Misegades, Cary, N.C., an aerospace engineer, aviation sales rep for U-Fuel, and president of EAA1114.


  1. Vinceramer says

    Graft, greed, and political coruption. Follow the money, thses EPA requirements were lobbied by the US corn growers association and the ethanol producers. Guaranteeing their susidies and market demand (high prices) at taxpayer expense…again

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