Intended for medium-duty and vocational applications, DuraStar® and WorkStar® Trucks are available with Cummins® ISL9 engine, which is rated up to 380 hp with up to 1,250 lb-ft of torque. DuraStar is also available with Navistar® N9 engine from 275–330 hp with 860–950 lb-ft torque. In addition, WorkStar is available with Navistar N9 and N10 engines from 275–370 hp with 860–1,250 lb-ft torque, and N13 engine from 365–475 hp with 1,250–1,700 lb-ft torque.