The Environmental Protection Agency (EPA) is finishing up labeling and other rules concerning E15 ethanol at the moment and an official introduction of the new blend is expected by this summer.

The move to increase ethanol content in gasoline by 50% has met with resistance from a number of sides, but the agency made the change official in January, after announcing it last October. The maximum ethanol content in gasoline at the moment is 10 per cent.

Car manufacturers have been among the most vocal in their resistance to the change to 15 per cent ethanol content, citing the corrosive effects of the additive on fuel system components.

To address the OEM’s concerns, the EPA has restricted the use of E15 to vehicles built in 2001 or later. Special E15 gas pumps will be required to minimize consumer confusion and will display warnings for owners of older vehicles. Vehicles built as “Flex Fuel” capable can use any grade up to E85 without problems.

By comparison, ethanol has a lower energy value than the equivalent amount of gasoline – something that drivers see manifested as slightly lower fuel economy results. Since all grades of gasoline may contain some portion of ethanol, it is difficult to compare pricing and energy content to understand fully whether or not it costs more to run a blended gasoline. It may be reasonable to assume that this is not by accident.

According to the EPA, over 150 million vehicles in use today were built since 2001 and are responsible for 74 per cent of the total annual gasoline consumption. By 2014, those number are expected to grow to 187 million eligible vehicles that consume 85 per cent of the total.

Other countries, however, have forged ahead without undue disaster. Brazil, for example, has run E20 and E25 blends since the late 1970’s.

Conversion of older (pre-1975) vehicles to use E15 or higher blends will require more than just replacement of fuel system components. Engine tuning needs to be revised as well, since the optimal air/fuel ratio changes depending on the amount of ethanol present.