According to the “Two Million-Mile Haul” B20 field documentation study being conducted by the Iowa Soybean Assn. (ISA), first-year results show 20% soy biodiesel blends (B20) perform similarly to diesel fuel in trucks.

“Although we have data from only the first year of the study, we are pleased with the results to date,” said Don Heck, coordinator of biotechnology and biofuels programs at Iowa Central Community College in Fort Dodge, IA. “Preliminary results are that B20 biodiesel performs similarly to 100% 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.”

The study is sponsored by ISA, Iowa Central Community College, Decker Truck Line Inc., Caterpillar Inc., the National Biodiesel Board, Renewable Energy Group Inc. and the U.S. Dept. of Agriculture.

For the study, Iowa Central Community College has been collecting and analyzing engine performance data and conducting in-house testing of both petroleum and B20. According to ISA, the study also examines how fuel additives affect the cold-flow properties when blended with ultra-low-sulfur-diesel (ULSD).

To test the differences between the fuels, two groups of 10 Decker Truck Line semi-tractors have traveled to either Minneapolis or Chicago using 100% No. 2 petroleum diesel or a blend of 20% biodiesel from Renewable Energy Group and 80% No. 2 petroleum diesel. Fuel efficiency, maintenance records and fuel quality for both groups are monitored.

According to ISA, average fuel efficiency was 6.29 mpg for the petroleum group and 6.15 mpg for the B20 group after more than 1.5-million miles were driven between Oct. 1, 2006, and Oct. 1, 2007.

“Right now, the B20 performs similarly to the 100% diesel fuel in this study,” said Heck. “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.”

“The study is important because it shows that biodiesel can be interchangeable with diesel for use in over-the-road trucking,” said Ed Ulch, an ISA director and treasurer of the National Biodiesel Board. “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.”

ISA reported a few problems with the B20 blend, admitting that a few filter plugging problems occurred early in the study. Changing the blend of the biodiesel fuel caused the rate of filter plugging to drop significantly. ISA reports that the B20, when mixed with a commercial fuel additive, didn't cause any cold-flow issues during winter driving.

View more Fleet Owner news relating to idle reduction, fuel conservation, fuel economy and diesel fuel prices.