URBANDALE, Iowa - The Iowa Soybean Association has partnered with others in a unique field study to examine the benefits of a 20 percent soy biodiesel blend (B20) in an over-the-road trucking company. First-year results of the study have shown that biodiesel performs similarly to diesel fuel in trucks.

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

The two-year study, called the “2 Million Mile Haul,” is sponsored by the ISA, 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. The study is believed to be the first comprehensive, publicly documented demonstration of B20 in over-the-road trucks.

“Although we have data from only the first year of the study, we are pleased with the results to date,” says Don Heck, coordinator of biotechnology and biofuels programs at Iowa Central Community College in Fort Dodge, Iowa.

“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,” says Heck.

Iowa Central Community College is responsible for collecting and analyzing engine performance data and conducting periodic in-house testing of the petroleum and B20-blend fuels for purity and consistency. The “2 Million Mile Haul” study also examines the effects of various fuel additives on the cold-flow properties of biodiesel blended with the new 2007 Ultra-Low Sulfur Diesel (ULSD.) The studies are focusing primarily on the cloud, plug and pour points.

The study consists of two groups of 10 Decker Truck Line Inc. semi tractors running with flatbed trailers on matched routes to either Minneapolis or Chicago. The control group uses 100 percent No. 2 petroleum diesel. The B20 test group uses a blend of 20 percent biodiesel from Renewable Energy Group, Inc. and 80 percent No. 2 petroleum diesel. Data is routinely analyzed for fuel efficiency, maintenance records and fuel quality.

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.

Driver fuel efficiency ranged from 5.72 mpg to 7.40 mpg for the control group, a 23 percent spread. For the B20 group, fuel efficiency ranged from 5.76 mpg to 7.00 mpg, an 18 percent spread among drivers.

Winter driving resulted in relatively few problems regarding cold-flow issues. Fuel for both groups was treated with a commercial fuel additive, and No. 1 diesel, a 40 percent blend, was used for a brief time during a severe cold snap in February 2007. No drivers experienced fuel gelling problems.

Early in the study, a few filter plugging problems occurred in trucks using the B20 blend. After changes were made in blending of the biodiesel fuel in early February 2007, the rate of filter plugging for the B20 group dropped significantly.

“We are continuing to investigate the causes of filter plugging that occurred last winter. The problem could be from improper blending techniques that have been remedied, or an interaction between biodiesel and the waxy particulates in new ULSD, or some combination of those factors,” says Heck.

“Right now, the B20 performs similarly to the 100 percent diesel fuel in this study,” says Heck. He noted that many people have told him anecdotally that biodiesel has increased their mileage and that may be the result of “cleaning out” an older engine.

“Oil test data shows no appreciable differences between the fuels. We expect that the B20 group of engines will show less wear than the control group,” says Heck. At the conclusion of the study, engines from both the control group and B20 group will be torn down for a closer analysis of engine wear.

Ed Ulch, a soybean producer and ISA director from Solon, Iowa, serves as treasurer of the National Biodiesel Board. He believes the 2 Million Mile Haul study lends credibility to commercial uses of biodiesel.

“The study is important because it shows that biodiesel can be interchangeable with diesel for use in over-the-road trucking,” says Ulch.

“When the engines are torn down at the completion of the study, the final results are expected to show less engine wear with biodiesel. The study should prove that biodiesel provides longer engine life,” says Ulch.

For more information on the first-year results of the 2 Million Mile Haul study, visit: www.twomillionmilehaul.com. Scroll down to “First Year Summary” for the full report.