Ultra-Low Sulphur Diesel (“ULSD”) is a D2 class diesel fuel distillate that results from a severe hydrofinishing process. This ULSD product is in line with the U.S. EPA's new mandate of less than 15 ppm sulphur content. It improves environmental conditions by reducing unwanted emissions into the atmosphere. ULSD has a high Cetane Index of 51, thus improving fuel combustion, reducing white smoke on startup, and tending to reduce NOX and PM emissions. ULSD generally looks lighter in color and has less smell than other diesel fuels.
ULSD is mostly for use in engines whose load size and speed remain relatively consistent. This diesel fuel has a greater energy output, and a better fuel economy. ULSD is required for use in model year 2007 vehicles and up equipped with advanced emission control systems in the U.S.