The phrase signifies a search for readily available diesel fuel containing a sulfur concentration not exceeding 15 parts per million (ppm). This specific type of fuel is mandated for use in most modern diesel engines. An example of its application is in over-the-road trucks and off-road equipment requiring fuel that meets current emission standards.
Reduced sulfur content leads to decreased emissions of sulfur oxides, contributing to improved air quality and reduced acid rain. The adoption of this fuel type has been instrumental in enabling advanced emission control technologies within diesel engines. Historically, the transition to this cleaner-burning fuel marked a significant step in mitigating the environmental impact of diesel engines.