Diesel Fuel (Off Road Low Sulfur)
Before EPA began regulating sulfur in diesel, diesel fuel contained as much as 5,000 parts per million (ppm) of sulfur. EPA began regulating diesel fuel sulfur levels in 1993.
Beginning in 2006, EPA began to phase-in more stringent regulations to lower the amount of sulfur in diesel fuel to 15 ppm. This fuel is known as ultra-low sulfur diesel (ULSD).
EPA’s diesel standards target emissions from two different sources:
Onroad (or highway) vehicles; and Nonroad engines and equipment.
Collectively, diesel standards reduce harmful emissions from both onroad and nonroad diesel sources by more than 90%.