Cummins Inc. reports that the B4.5, B6.7, and L9 engine platforms are compatible with paraffinic renewable diesel fuels meeting the EN 15940 specification for for paraffinic diesel fuel made from synthesis or hydro-treatment. Both on- and off-highway versions of the B6.7 and L9 platforms and all vintages are approved to use paraffinic diesel fuels in North America.
The development helps further reduce the carbon footprint of Cummins-powered bus, truck, agricultural, and construction fleets. Compared with conventional fossil-based diesel, paraffinic diesel fuels offer the potential to reduce greenhouse gas emissions by 40-90% over the total life cycle of the vehicle.
Paraffinic diesel fuels can be used as a 100% substitute for standard EN 590 or ASTM D975 Ultra-Low Sulfur Diesel (ULSD) without requiring any change to the Cummins engine. Paraffinic diesel can easily be blended with standard diesel at varying percentages, including winter-grade fuels, and has the same stability and cold properties as conventional diesel, which means it can be used and stored in the same ways. 
The Cummins B6.7 engine.
Cummins led an 18-month field trial running 100% paraffinic diesel fuel in order to understand changes in engine performance, aftertreatment effects, and fuel system durability. Engine performance remained stable and consistent while using the paraffinic fuel, and customers should not expect to see any differences. Depending on the application and the engine duty cycle, a fuel economy detriment of 0-6% is expected due to the lower density of paraffinic fuels compared with regular diesel fuel.
