Everyone expected the Heavy Duty Rams to get the same interior and exterior treatment as the updated 2013 Ram 1500, but the all-truck brand has delivered much more with claimed best-in-class towing, payload, frontal load and gross vehicle weight rating.

The updates you'll be most interested in are under the hood. The biggest news for serious haulers is that the vaunted Cummins diesel now comes in three flavors. The lowest output version makes a stout 350 horsepower and 660 lb-ft of torque and comes with the only six-speed manual transmission in the segment. That's an improvement of 50 lb-ft from last year's stick-shift diesel, and it's matched with a new "wear-compensating" clutch that's supposed to feel like new until the day you finally wear it out.

If you don't feel like rowing your own, or you need more power, the second option will net you 370 horsepower and 800 lb-ft of torque routed through a six-speed automatic. For those not willing to simply upgrade to a Peterbilt, the "High-Output" Cummins cranks out 385 horsepower and an even more ridiculous 850 lb-ft of torque and puts it through a new Aisin six-speed automatic.

Even more important than all that for you serious truckers, though, is the addition of Diesel Exhaust Fluid. For a few years, Ram guys were able to boast that their diesels didn't have to worry about running out of DEF, but no more. The on-demand system features a heated tank for cold climates and, unlike some competitors, won't cut engine power when fluid runs low. You'll still have to refill it, though. The fill port is located right next to the capless diesel fuel filler.

The upgraded diesel has other tricks up its sleeve. All the cooling systems, from the engine to the transmission to the intercooler to the exhaust gas recirculation system, have been upgraded. A selective catalyst reduction system can also be added and is compatible with B-20 biodiesel. On the other end, a new Active Air Intake system can pull air from the front of the truck, under the hood away from snow, or both for maximum power and efficiency. Add it all together and Ram claims fuel economy will jump 10 percent and oil changes can be stretched to 15,000 miles.

The 5.7-liter Hemi gasoline V-8 engine is now available on both the 2500 and 3500 models and continues to produce 383 horsepower and 400 lb-ft of torque, meaning it didn't get the same bump as the 1500. In either 2500 or 3500 trucks, it comes only with the six-speed automatic gearbox.

The improvements aren't just in the engine bay. Ram has also beefed up the drivetrain with a new 11.8-inch rear axle and a front axle that automatically disconnects to reduce drag in the drivetrain and pick up an extra mile per gallon. Two new Borg Warner transfer cases are available, either manual or automatic, and each features a 2.64 crawling ratio and a locking differential.

Making use of all that power requires a sturdy frame. To beef things up, Ram added more cross-members, widened the front rails, and fully boxed the rears. A factory installed rear cross-member includes provisions for gooseneck and fifth-wheel hitches. The conventional hitch at the rear has been upgraded to a Class 5 and can pull an astonishing 17,000 pounds with up to 1800 pounds on the tongue. Also attached to the frame are a new three-link front suspension and a Hotchkiss leaf spring rear suspension that up the payload and gross vehicle weight ratings, though Ram won't tell us yet how much. "Best-in-class" is all it'll say. Keeping the load in check is a standard electronic stability control program and an upgraded steering rack.

You'll be more familiar with some of the other upgrades. Like the Ram 1500, the 2500 and 3500 get new exterior and interior styling. The latter includes Chrysler's latest 8.4-inch UConnect infotainment system on the revised center stack, new climate controls, new gauges with a customizable display in the center, and an out-of-the-way dial shifter on the dash. Other features include keyless entry, starting, and remote starting; HD Radio; advanced text messaging that will allow you to dictate text messages through the voice recognition system; central power locking not just for the doors, but also the tailgate and the optional RamBoxes in the bed sides; and not one, but two, backup cameras. The first is your standard camera mounted next to the handle on the tailgate. The second is mounted in the center high-mount stoplight on the back of the cab looking down onto the bed to aid in lining up your gooseneck.

For fleet buyers, Ram adds a vehicle system interface module that allows easy access to the truck's electrical systems for factory and aftermarket modules to monitor performance and maintenance. Ram even went so far as to move the badges off the door so they'd be out of the way of your company's logo. Did we mention all these upgrades also apply to 3500, 4500, and 5500 commercial chassis-cab trucks? Those also claim best-in-class gross axle weight ratings on the 4500 and 5500 as well as the largest fuel tanks and brakes in the class and a best-in-class dual 220-amp alternator charging system.

Clearly, then, there's something for everyone on the new Heavy Duty Ram. It looks better; it's got more features; it's got more power; and it can tow and haul more than ever before. Throw in a claimed best-in-class powertrain warranty of five years or 100,000 miles, and what more could a truck guy ask for?