The project started in early 2019 with the goal of optimizing cylinder deactivation strategies for diesel engines, which could result in emission reduction benefits. Advancements through the project are expected to help address future, more stringent NOx regulations. The collaboration work was carried out on a Cummins X15 Efficiency Series 6-cylinder diesel engine, which offers class-leading fuel economy. The joint development team modified the engine system to integrate and leverage Tula's Dynamic Skip Fire (DSF®) control algorithms to command combustion or deactivation on a cylinder event basis. On the challenging low-load cycle being proposed by the California Air Resources Board, modeling of dDSF technology predicted reductions in tailpipe NOx (oxides of nitrogen) emissions while simultaneously reducing CO 2 (carbon dioxide).