COLUMBUS, Ind. — The Cummins B4.5, B6.7, and L9 engine platforms are compatible with paraffinic renewable diesel fuels meeting the EN 15940 specification, the engine manufacturer announced on Wednesday.

Both on-highway and off-highway versions of the B6.7 and L9 platforms and all vintages are approved to use paraffinic diesel fuels in North America.

Cummins' approval of the use of renewable diesel with the B6.7 and L9 engines aligns with the recent introduction of EN 15940, a final European CEN specification for paraffinic diesel fuels, including hydrotreated vegetable oil, gas-to-liquids, and biomass-to-liquids.

Operators of Cummins-powered trucks and buses are required to source all paraffinic fuels from high-purity suppliers meeting EN 15940, which ensures that the fuel contains the necessary lubricity additive for use in a diesel engine.

According to the company, the approval of renewable diesel 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% to 90% over the total life cycle of the vehicle, Cummins said.

Paraffinic diesel fuels can be used as a 100% substitute for standard EN 590 or ASTM D975 ultra-low sulfur diesel without requiring any change to the Cummins engine. No additional engine maintenance is required when using paraffinic fuels meeting the EN 15940 specification, and the same fuel filters are retained.

Cummins said that paraffinic diesel can easily be blended with standard diesel at varying percentages, including winter-grade fuels, and it has the same stability and cold properties as conventional diesel, which means it can be used and stored in the same ways.

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. The manufacturer reported that engine performance remained stable and consistent while using the paraffinic fuel. Depending on the application and the engine duty cycle, a fuel economy detriment of up to 6% is expected due to the lower density of paraffinic fuels compared with regular diesel fuel.

An analysis of the aftertreatment system showed that each subsystem — the diesel oxidation catalyst, diesel particulate filter, and selective catalytic reduction — remained stable throughout the test with performance similar to that of regular diesel fuel, Cummins found. The materials in the fuel system equipment (O-rings, injectors, and pumps) are all compatible with EN 15940 diesel fuels.

"The use of paraffinic diesel allows customers to minimize their emissions-based footprints without additional capital investment,” said Jim Fier, Cummins’ vice president of engineering. “Plus, they have the comfort of knowing that Cummins conducted a thorough analysis prior to approval.”

Other light-duty, heavy-duty, and high-horsepower platforms are currently undergoing a similar validation plan on 100% paraffinic fuels, and Cummins said that it will be announcing the results of those studies throughout 2017.