Dieselcraft Fluid Engineering of Richmond VA said it is seeking a limited number of bus and truck fleet owners and operators to participate in a diesel fuel efficiency test.

The company said that after the 30-day period, the test subjects will be supplied with a mechanical device that will be installed on the system's fuel filter. The test subject then will be asked to record the data as before for 60 days and supply that data to Dieselcraft each Friday for tabulation.

Companies and or government agencies interested in participating in these tests must have more than 20 vehicles and must have computer-generated recordkeeping for fuel consumption and miles driven.