Dodge Ram gets medium-duty upgrade.

An important part of DaimlerChrysler’s plan to turn around the ailing Chrysler Group is to build on its strength in producing commercial-grade trucks. This year marks Dodge’s return to the medium-duty segment, with the Ram 4500 and 5500.

Slated for production in Mexico and available in the fall, the “box off” models will come powered with a 6.7-liter, six-cylinder, in-line Cummins turbo diesel that produces 305 hp and 610 ft-lb of torque. Buyers can choose between two- and four-wheel drive, six-speed manual and automatic transmissions, as well as regular and crew cabs on six wheelbases.

The drivetrain and chassis, with 50,000-psi-strength C-channel frame rails, will accommodate work bodies driven by power takeoff. Dodge says the trucks will last 350,000 miles before needing an overhaul.

Introduced Feb. 7 at the Chicago Auto Show, the models have rugged styling akin to other Rams, with solid-touch door handles and control knobs. Dodge also will offer upscale options like leather upholstery, wood trim and navigation assistance.