It's well known that a gallon of gas with ethanol won't take your car or truck as far down the road as a gallon of regular gas, even if it does so with lower greenhouse gas emissions. The real question is how consumers will react--even in Iowa--if Congress (or states) rush ahead with plans to put much, much more ethanol in our tanks, much sooner, at the same time we're all desperate to get more miles per gallon.

E85, flex-fuel vehicles continue to be pushed by Ford and other companies, in a bid to make the type of fuel, instead of fuel economy, the consumer culture's indicator of greenness. Take a gander at this fine example of a green, flex-fuel Ford vehicle. Why, it's all about the E85, in a truck design cued off a locomotive.

"The F-250 Super Chief’s bold, American design, first-class comfort and exceptional traveling range were inspired by the Atchison, Topeka and Santa Fe Railway’s Super Chief locomotive."

The corn lobby is delighted with this approach, naturally. House Ag Committee Chairman Collin Peterson underscored again yesterday what we've known all year: the energy bill with a gigantic increase in the renewable fuel standard (read "boatloads more corn ethanol") is more important to much of the crop subsidy lobby right now than the farm bill.

If consumers reject this proposition on pocketbook grounds, however, the bait and switch will quickly acquire the appeal of. . . leftover bait.

This chart from the EPA's web site, fueleconomy.gov, presents some eye-popping reductions in fuel economy for the handful of "flex fuel" E85 vehicles now on the road in America if they in fact fill up with 85 percent ethanol. (Flex-fuel vehicles have engines capable of running on either regular gas or up to 85 percent ethanol, or E85. Most vehicles of recent vintage can only use the standard mix of 90 percent gasoline/10 percent ethanol.)

It looks to be about a 25-30 percent MPG reduction for most vehicles, and that's an additional drop from the newly lowered, somewhat more realistic MPG estimates that EPA required on new cars and trucks starting with the 2008 model year now in showrooms. So we're talking lousy fuel economy with full E85 ethanol in American vehicles now on the market.

For instance, a Chrysler Town and Country minivan, 2WD with 6 cyl automatic, running on gasoline, will average 18 MPG (highway/city combined ) but only 13 MPG on E85. Assuming $3.01/gal for regular and $2.63/gal for E85, EPA says a 25-mile trip in the Town and Country would cost $4.18 on gas and $5.06 on E85. Annual cost, even at the much lower per gallon price for E85: $2,510 for gas, $3,034 for E85, a $524 difference (maybe a couple of monthly payments).

For the Ford Explorer (2WD, 6 cyl, auto), the combined MPG drops from 15 to 11 MPG with a switch from gas to E85. In a Taurus Wagon, it plunges to 14 from 20.

Typical drivers would probably choose to buy regular gas from time to time, especially since E85 isn't widely available (though state and federal subsidies are also being sought for retail infrastructure). So the MPG gaps would not be that great. But then, neither would the greenhouse gas reductions.

And greenhouse gas reductions are the good news with E85. Even with the lower MPG, the greenhouse gas emissions for that Town and Country would be in the range of 8.5 tons per year with E85, vs. 10.2 tons with gasoline, a 17 percent reduction. (EPA calls these "full fuel-cycle estimates"of greenhouse gas emissions, which "consider all steps in the use of a fuel, from production and refining to distribution and final use. This gives a more complete picture of how using a particular fuel contributes to climate change.")

Most consumers probably want greenhouse gas reductions. But they definitely want more miles per gallon, and therefore less of their money left at the gas station. Even if we do start calling it the "fueling station."

On the other hand, one could see the E85 push as another step in Detroit's brilliant "buy foreign" campaign. Now in full swing, its apparent goal is to get Americans into smaller, better made, more fuel-efficient foreign cars, while closing costly domestic auto plants and laying off expensive U.S. autoworkers.

I guess for U.S. automakers, almost anything beats a headlong rush towards great cars that get great mileage. And sell.