A Hyster forklift was part of one of the largest biodiesel studies funded by the US Department of Defense (DoD).

The DoD's Environmental Security Technology Certification program funded the project, which was a joint effort between the Naval Facilities Engineering Service Center, the University of California Riverside College of Engineering, the Center for Environmental Research and Technology, the US Army Aberdeen Test Center (ATC) and various military bases.

The goal of the study was to expand the database of emissions from military applications and provide a greater emphasis on emissions from biodiesel produced from vegetable oil sources (yellow grease).

The 10 vehicles and pieces of equipment tested included the Hyster forklift, two medium-duty trucks, two Humvees, a heavy-duty diesel truck, a bus, two stationary backup generators and an airport tow vehicle.

They were acquired from southern California military bases of the Aberdeen Proving Grounds in Aberdeen, Maryland.

The 2001 Hyster 65 forklift with a 2.6L Perkins engine was tested with an on-road, CARB-certified ultra-low sulphur diesel (ULSD) fuel and a soy-based biodiesel obtained from World Energy (B20-Soy fuel).

For the forklift, the test run simulated forklift usage including idling, hydraulic usage while idling, and driving with and without hydraulic usage over a 3.6 mile (5.8km) test run.

The ATC used EPA's real-time on-road vehicle emissions reporter to record NOx, HC, CO, CO2 and other vehicle-operating parameters for the forklift.

A 20% increase in CO emissions was found for the B20-Soy fuel and the differences for total hydrocarbons and NOx were small and likely within experimental variability, the study found.

The study was published in the Atmospheric Environment journal in September.