A two-year-long study is showing that biodiesel is as good as regular diesel for over-the-road trucks.

The “2 Million Mile Haul”… halfway through the study at this point… is looking at the benefits of using 20 percent biodiesel blend (B20) and is being conducted by the Iowa Soybean Association (ISA) in partnership with Iowa Central Community College, Decker Truck Line Inc., Caterpillar Inc., the National Biodiesel Board, Renewable Energy Group, Inc. and the U.S. Department of Agriculture. This story on the Energy Current web site says it’s believed this is the first comprehensive, publicly-documented demonstration of B20 in big rigs:

“The trucking industry is by far the single largest consumer of diesel fuel, using 38 billion gallons annually,” said Grant Kimberley, ISA director of market development. “This study demonstrates in a real-world environment that biodiesel can be used successfully year-round.”

Don Heck, coordinator of biotechnology and biofuels programs at Iowa Central Community College in Fort Dodge, Iowa, said, “Although we have data from only the first year of the study, we are pleased with the results to date. Preliminary results are that B20 biodiesel performs similarly to 100 percent diesel. We found a slight decrease in overall fuel efficiency for the B20 group of trucks, but it was not statistically significant. In fact, the difference was several times smaller than the driver-to-driver variability in fuel efficiency within each group.”

More than 1.5 million miles had been logged by the end of the first year, from Oct. 1, 2006 to Oct. 1, 2007. Overall fuel efficiency, including idle time, was slightly reduced in the B20 group. Average fuel consumption for the control group was 6.29 miles per gallon (mpg) and for the B20 group it was 6.15 mpg. The fuel efficiency difference of 2.2 percent between groups is not considered significant, especially when compared to driver variability.

Proponents of biodiesel believe the test will help the commercial credibility of the green fuel.