The Texas Diesel Fuels Project, Part 4: Fuel Consumption, Emissions, and Cost-Effectiveness of an Ultra-Low-Sulfur Diesel Fuel Compared to Conventional Diesel Fuels

The Texas Department of Transportation (TxDOT) began using an ultra-low-sulfur, low aromatic, high cetane number diesel fuel (TxLED, Texas Low Emission Diesel) in June 2003. They initiated a simultaneous study of the effectiveness to reduce emissions and influence fuel economy of this fuel in comparison to 2D on-road diesel fuel used in both their on-road and off-road equipment. The study incorporated analyses for the fleet operated by the Association of General Contractors (AGC) in the Houston area. Some members of AGC use 2D off-road diesel in their equipment. One off-road engine, two single-axle dump trucks, and two tandem-axle dump trucks were tested. The equipment tested included newer electronically-controlled diesels. The off-road engine was tested over the TxDOT Telescoping Boom Excavator Cycle. The dump trucks were tested using the “route” technique over the TxDOT Single-Axle Dump Truck Cycle or the TxDOT Tandem-Axle Dump Truck Cycle. Compared to 2D on-road diesel fuel, for the operating cycles and engines/vehicles tested, TxLED showed an average decrease in NOx emissions of about 5.5%. The results of cost-effectiveness analyses for the TxDOT and AGC fleets are also discussed.