Revealed at the 2009 Chicago Auto Show, the 2010 Dodge Ram Heavy Duty lineup continues its trend toward greater comfort and improved towing prowess -- punctuated by an expressive, big-rig design. Hoping to build upon the momentum generated by its well-received light-duty Ram late last year, Dodge has added a crew cab option to the HD lineup for the first time, and boasts of improved overall capability and interior upgrades.

With a 90% take-rate, the 6.7L Cummins diesel is clearly the 2500/3500 Ram HD's most popular engine choice. As such, the Cummins hasn't received any changes and still pumps out an extra stout 650 lb-ft of torque at 1500 rpm and a peak 350 hp at maximum high-idle speed of 3000 rpm. In an effort to further clean up emissions, a particulate filter has been added to the exhaust system that Dodge claims drops NOx emissions by 90%. The 50-state-legal diesel meets 2010.5 emissions standards and requires oil change intervals at 7500 miles. Major overhauls can wait until the odo hits 350,000 miles.

Also available is the 5.7L HEMI V-8. Updated in 2009, it produces 383 hp and 400 lb-ft of torque at 4000 rpm, thanks to an increased compression ratio, active intake manifold, and variable valve timing.

Those opting for the diesel can choose between the G56 six-speed manual and a 68RFE six-speed automatic. A heavy-duty 545RFE five-speed automatic is the sole transmission option on the V-8. Five- and six-speed automatics include an Electronic Range Select, which allows the driver to limit the highest gear and manual up- and down-shifts.

For four-wheeling duties, purchasers get their choice of two transfer cases: a manual operable NV271 unit for the ST and Power Wagon and an electric, shift-on-the-fly NV273 case on SLT and Laramie models. Available axle ratios consist of 3.42, 3.73, 4.10, or 4.56.

With the right equipment pairing (say, a diesel, automatic 3500 dually using the 4.10 rear axle), the Ram offers a Gross Combined Weight Rating of 25,400 lb. Its towing capability stands at 18,500 lb thanks, in part, to a hydroformed box frame that rides on a coil-spring suspension in the front and a multileaf-spring design in the rear.