While the legal status of E15 gasoline is in doubt, the Environmental Protection Agency is moving forward with plans for it to roll out before this summer's driving season.

That means that drivers will have to pay attention to the labels on their gas pumps, making sure that E15 is only used for cars built in 2001 or later. Older vehicles have not been approved for the higher ethanol blend, and should stick with the current E10.

75 percent of demand

More than 150 million vehicles built since 2001 are on U.S. roads, and that they represent three-quarters of the gasoline consumed. The EPA estimates that fraction will rise to 85 percent by 2014.

The new E15 gasoline blend has 15 percent ethanol, up from the current maximum of 10 percent that has been in effect since 1978.

It's unclear how individual service stations will handle the transition: Some may install new tanks for E15, while others could opt for blender pumps, which blend ethanol with gasoline to create either E10 or the new E15.

Labels coming soon

EPA administrator Lisa Jackson told Congress last week that the agency is moving ahead and hopes to finalize the proposed design of labels for pumps to alert drivers about the new fuel, and how it should be used.

Rules for those labels should be issued "in the next few months," she said. This spring, the agency will also officially register the new E15 fuel, a step that must be completed under the Clean Air Act to make the fuel legal to sell.

Two goals

Raising the amount of ethanol in gasoline, in theory, accomplishes two goals. First, it adds no "new" carbon to the atmosphere, because the plants it's derived from have already absorbed carbon from the air. So the CO2 released when it's burned is simply being returned to the air, rather than increasing the total.

Second, because ethanol is refined in the United States, it displaces gasoline that has to be made from imported oil. That improves both energy security and the U.S. trade deficit.

Almost all ethanol used in U.S. gasoline, however, is made from corn--the least productive feedstock available. That has led to sharp criticism over its ability to displace food production from prime agricultural land, and questions about its total "wells to wheels" carbon balance.

Gasoline demand falling

But under current law, ethanol use must increase from last year's 11.1 billion gallons to 36 billion by 2022. That's the amount specified in the Energy Independence and Security Act passed by Congress in 2007. Industry observers have consistently questioned whether that volume of ethanol can even be produced, let alone whether it is good policy.

It's worth noting that the recession, gradually increasing fuel efficiency in new vehicles, and more ethanol in the fuel burned have collectively led to a decline in U.S. gasoline consumption. For the record, U.S. gasoline demand peaked in 2006 and has fallen since.



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