What is clean about diesel?
Diesel vehicles produced since 2007 require ULSD (Ultra Low Sulfur Diesel) to run properly. Previously the US had LSD (Low Sulfur Diesel) which ran at 500 ppm Sulfur. ULSD saw a substantial reduction, down to 15 ppm Sulfur. This 97% reduction in the soot generating sulfur is what makes this fuel cleaner.
Vehicles that require ULSD also are equipped with other controls to further reduce emissions. A particulate filter catches carbon from the exhaust and regenerates itself in a cycle. During this regeneration cycle the filter gets extremely hot and burns these carbon particulates. This is controlled by the vehicle’s computer and done under certain circumstances.
Other vehicles may contain a urea-injection system which sprays a fluid in the exhaust to chemically reduce NOx. These systems are commonly found on European diesel SUVs and are referred to as “AdBlue”.
