-Diesel Fuel (DF)
-Shell Middle Distillate with lubrication additives, (Gas to Liquid Fuel, or GTL)
-Premium Diesel Fuel (PDF), which was a biodiesel blend of 20 percent Rapeseed Oil Methyl Ester (RME) with 20 percent GTL and 60 percent DF
-A blend of 5 percent biodiesel and 95 percent GTL (B5GTL).
The findings show that GTL had lower emissions that DF, and the biodiesels had lower hydrocarbon, carbon monoxide and particle mass emissions. You can read the entire 43-page, chart-filled PDF here. The tests were conducted on a truck engine that meets Euro 3 standards and was also testing what might happen with changes in diesel engine technology. Another reason for the study was to determine the possible characteristics of a biomass to liquid fuel prototype fuel.
[Source: UFOP via Dieselnet]