CommentaryUsers of likely were startled recently when the Internet portal’s homepage was wallpapered with a maze of corncobs.

It took a second to realize it was part of an elaborate General Motors “Live Green Go Yellow†advertising campaign to promote its corn-based E85-compatible models, equipped with flexible-fuel engines.

E85 is a blend of 85% ethyl alcohol (ethanol) and 15% gasoline. Ethanol primarily is distilled from corn in the U.S. and sugarcane in Brazil. A flex-fuel car can run on gasoline or ethanol or a mix of the two.

GM is offering nine E85 flex-fuel models this year and is expecting to sell 400,000 units in addition to the 1.5 million GM E85-capable vehicles on the road today – although by some counts, only a scant 1% of those car owners actually use E85.

Ford also is on the corn wagon, pledging to sell 250,000 E85 flex-fuel vehicles annually by the end of the decade.

GM says its goal is to increase E85 awareness and market acceptance of a fuel that advocates insist is an immediate step toward reducing U.S. reliance on foreign oil, a point hammered home by President Bush in his State of the Union address.

“We are trying to start a movement that will heighten the focus on the need to diversify our energy needs with ethanol,†Brent Dewar, GM executive vice president-marketing and advertising, says in announcing the campaign at Washington’s recent auto show.

The auto maker even includes a “GM Cornulator†on its promotional LiveGreenGoYellow website that calculates the amount of petroleum saved with E85.

Yet, the issue is not so much the fossil fuel saved as the amount of E85 to be found.

In 2004, there only were 150 service stations nationwide selling the fuel. And despite the number rising to 600 in 2005 and to 2,000 by the end of this year, according to the National Ethanol Vehicle Coalition, they still will be few and far between among the country’s 168,000 gas stations.

Ethanol detractors insist the production of ethanol fuel doesn’t make economic sense due to the quantity of petroleum products consumed in the ethanol manufacturing chain: crop fertilizers, diesel fuel for tractors and tanker trucks and the energy to fuel ethanol refineries.

Advocates say those concerns will be negated by the coming energy revolution that will be based on vegetable oil, wind, solar and hydrogen power.

Indeed, Brazil has made significant progress in replacing gasoline with ethanol fuel. Cars with flex-fuel capability represented 78% of the total number of vehicles sold last year, Tom Stephens, GM group vice president-GM Powertrain, says.

All things being equal, E85 still has its drawbacks. While up to 20% less expensive at the pump than regular unleaded, the fuel contains 27% less energy than gasoline, a reduction in fuel economy by up to 12% in real-world driving.

It all boils down to whether conscientious consumers want to kick their addiction to oil. With apologies to Kermit, no one says it will be easy going yellow.Â