A costly federal government effort to put more workers into vehicles powered by ethanol and other fuel alternatives has suffered endless problems, many of them caused by buying vehicles before fuel stations were in place to support them, according to the Washington Post. As a result, more than 92 percent of the fuel used in the government's alternative-fuel fleet continues to be standard gasoline.

Federal agencies have gradually increased their fleets of alternative-fuel vehicles, a majority of them "flex-fuel," capable of running on either gasoline or ethanol-based E85 fuel. The increase took place under a mandate from Congress. But many of the vehicles were sent to locations hundreds of miles from any alternative fueling sites, the analysis shows.

A 2005 law -- meant to align the vehicles with alternative-fuel stations -- now requires agencies to seek waivers when a vehicle is more than five miles or 15 minutes from an ethanol pump.

The latest generations of alternative vehicles are a big part of the problem. Often, the vehicles come only with larger engines than the ones they replaced in the fleet. The federal program known as EPACT has sometimes increased gasoline consumption and emission rates, the opposite of what was intended.

For example, the Postal Service estimates that its 37,000 newer alternative-fuel delivery vans, which can run on high-grade ethanol, consumed 1.5 million additional gallons of gasoline last fiscal year because of the larger engines.

The vehicles that would allow the agency to meet federal mandates were available in six- and eight-cylinder models -- not the four-cylinder variety it traditionally purchased. Alternative fuel was used less than 1 percent of the time in 2007-2008.

The Department of Energy defended its efforts, saying The U.S. government is promoting diversification of alternative fuels and vehicles and is working with private industry partners to develop and grow infrastructure of alternative fuels."

Department of Energy spokeswoman Jennifer Scoggins pointed to a two-year growth spurt of E85 stations, which dispense fuel that is 85 percent ethanol and 15 percent gasoline. Since 2006, ethanol stations have increased from 481 to 1,689 nationally, but most are in the Midwest. Station owners face a vexing challenge: how to compete with more than 160,000 gasoline stations located on nearly every street corner, especially as gas prices drop.