Cummins detailed the latest generation of its medium-duty engines, unveiling the 2017 B6.7 and L9 engines at the NTEA Work Truck Show in Indianapolis, Ind.

The two models are the most recent versions of Cummins midrange diesel engines designed for use in medium-duty applications.

The 2017 B6.7 engine features a range of 200 to 325 hp and 520 to 750-lb.-ft. of torque. The company touted increases in fuel economy for the entire range of power ratings and the engine has been designed for stop-and-go duty cycles. Engines rated up to 260 hp offer an increase in fuel economy of up to 7% over the current generation while engines rated from 280 to 325 hp can expect up to a 5% increase.

"The B-Series engine is the blue jeans of the American trucking industry,” said Srikanth Padmanabhan, vice president of engine business at Cummins. “And it will never go out of style.”

The 2017 L9 engine features a power range of 260 to 380 hp and 720 to 1,250 lb.-ft. of torque. New for 2017 is a 350 hp, 1,150-lb.-ft.-rated version designed to maintain more power and torque across a wider rpm range. It is suited for vocational duty cycles.

Cummins also unveiled the 2017 Single Module aftertreatment system. The system combines the diesel oxidation catalyst, diesel particulate filter and selective catalytic reduction systems into a single canister. The midrange system features up to a 70% reduction in space claim and up to a 30% reduction in weight over current aftertreatment systems, according to Cummins.

Diesel exhaust fluid dosing with the UL2 Urea Dosing System eliminates the need for engine coolant lines to and from the DEF injector, reducing installation complexity and allowing for easier serviceability. The injector's atomization nozzle reduces the risk of deposit formation, and offers a freeze-robust design and improved reliability. Cummins offers a range of systems sized for the engine and rating to ensure more efficient operation and improved fuel efficiency across a range of applications.

All Cummins engines are backed by the company’s support network in North America, with over 3,500 authorized repair locations to service vehicles.