INDIANAPOLIS — Cummins Inc. unveiled its medium-duty engine lineup March 1 at the Work Truck Show here. It includes mechanical and electronic changes to meet greenhouse-gas emissions regulations, but it also features rebranding the 6.7-liter B series and the 9-liter L, reverting to displacement in the engine designation.
“Cummins is redefining classics — by introducing the newest-generation B and L Series engines — the B6.7 and L9,” said Brett Merritt, executive director of on-highway business for Cummins.
The B6.7 offers fuel-economy gains of up to 7% and new top ratings with a maximum 325 hp and 750 pound-feet of torque, according to Cummins. The engine is now offered in an economy range of 200 to 260 hp and performance ratings from 280 to 325 hp, with slightly lower economy gains of 5%.
The engine is optimized for stop-and-go duty cycles and is stop-start ready, according to Cummins. That means it is capable of switching off when at a standstill, but this ability has yet to be implemented because it requires interaction with transmission and vehicle manufacturers to make the feature available.
The B series engine traces its heritage back to a 5.9-liter displacement, 6-cylinder engine launched in 1984. Since then, more than 16 million midrange engines have been manufactured around the world, Merritt said.
The L9 is the 2017 iteration of the previous ISL with 260 to 380 hp and 720 to 1,150 pound-feet of torque. For vocational users, a new rating of 350 hp and 1,150 pound-feet of torque offers a wider rpm range for tough duty cycles.
The L engine has been available fueled by natural gas, as the ISL 9G. At the launch, the B diesel engine was displayed as a natural-gas engine for the first time, said Amy Boerger, vice president of Cummins’ North American engine business.
Cummins’ Connected Diagnostics telematics service is also offered on these midrange engines.
The company also displayed its repackaged aftertreatment solution, which puts diesel oxidation catalyst, diesel particulate filter and selective catalytic reduction systems into a single canister. This midrange aftertreatment system reduces space up to 70% for easier packaging on medium-duty chassis. It also reduces weight by 30% compared with Cummins’ current aftertreatment systems.