The United States Postal Service has been testing various kinds of flex fuel vehicles over the past several years. 30,000 of their trucks, in fact, run on something other than gasoline, such as compressed natural gas, clean diesel, propane, or electricity. But as AutoblogGreen reports, the USPS's flexfuel experiment is generating some poor results—mainly when it comes to E85-capable vehicles.

Those trucks not only saw 29 percent less fuel efficiency, but also ended up forcing the USPS to consume 1.5m gallons more gasoline than before, the report said. "Why? Because the USPS couldn't buy and use E85 everywhere it wanted to and so the flexfuel engines - which were larger than the ones they replaced - were thirsty and burned more fuel."

Normally, PDF links are a scary thing to be avoided at all costs. But the USPS study consists of clear, well-written slides going over each of the options, how they performed, and what their next steps will be. It's good stuff—why can't all government documentation be this clear?

(Although the E85 results are no surprise at all—it's been clear for years that there are major problems with this approach.)

(Thanks to Warren W for sending this in)