The new HFE (High Fuel Efficiency) model boasts a headline-grabbing 18-mpg city/25-mpg highway EPA fuel economy rating. It's built on the lightest-possible Ram 1500 chassis, a Regular Cab 4x2 with the 6 foot, 4-inch bed, with an 8-speed automatic and tall 3.21:1 final drive. This 3.6-liter V-6-powered truck features stop/start technology that automatically shuts off the engine at stoplights. Then when the driver lifts his foot off the brake, the 12-volt starter cranks the engine back to life. The system has a high-capacity battery and alternator to withstand the rigors of frequent engine starts. With about a second of crank time each the engine is restarted, it's not as seamless in operation as some mild hybrids with 36-volt systems, like the Chevy Malibu ECO, which restart the engine smoothly and in a fraction of a second, but it's certainly a system you can live with. Ram gives drivers the option of turning stop/start off if desired via a dash switch.

Then there's the default choice, the legendary 5.7-liter Hemi V-8, which is standard on the Express, Big Horn/Lone Star, Outdoorsman, Sport, R/T, Laramie, and Laramie Longhorn. Like the 3.6-liter V-6, it has variable valve timing for a broad torque band. It also features mileage-improving cylinder deactivation that shuts off fuel to four of the eight cylinders under low-load conditions when full power is not required. Ram tells us the new Torqueflite 8 transmission teamed with the Hemi and,the 3.92:1 final drive is expected to be in excess of 11,000 pounds. An optional integrated trailer brake controller is located within easy reach on the center stack.

Take a peek under the Ram's massive hood and there's definitely more room behind the Ram's grille cross-hairs for more engine--as in a certain longer inline-six oil-burner! The new Pentastar V-6 is so far back in the chassis, it barely edges forward of the front axle centerline. Even the 5.7-liter Hemi V-8 looks like it's lost inside the cavernous engine room. Chrysler executive's lips are sealed on this one.

Speaking of the new Torqueflite 8, it comes in two flavors: a light-duty ZF 8HP45 with 332 lb-ft of torque capacity for use behind the new 3.6-liter V-6 and a medium-duty 516 lb-ft-capacity ZF 8HP70 unit teamed with the 5.7-liter Hemi V-8. Both 8-speeds have identical, widely spaced ratios, with a super-low first gear for quick launches and two tallish overdrive ratios up top. You might think with that many gears the 8-speed would be tripping all over itself, constantly swapping gears to find the optimal ratio. But the reality is this gearbox does a great job of quickly zeroing in on the right ratio with its five closely spaced middle gears for any given throttle position, road speed, or load--much better than the old gearbox handled just six cogs. The wider selection of ratios helps keep the engine running at its most efficient rpm. The 8-speed's shifts are milliseconds quick and seamless to boot.

The new 8-speed's dash-mounted transmission range-select knob has a precise, yet substantial feel -- something more than just a big radio volume knob. There's a delicate balance that had to be achieved to find a shifter solution that feels natural to pickup truck owners with work gloves or weathered, calloused hands more accustomed to moving a hefty lever a few inches and not even thinking about it. Getting the previous floor shifter off the console frees up valuable stash space right where you want it. And the advantage over the previous column-shift design is a clear sight line to the center stack controls for 4WD, climate, and audio. It just takes a little getting used to the first few times you reach for a lever-type shifter that isn't there anymore when trying to make a quick 3-point turn on a crowded street. Selections are Park, Reverse, Neutral, and Drive. There is no Low that can be selected by twisting the knob; downshift buttons on the right steering wheel spoke accomplish this task. These are small and could be mistaken for audio tuning buttons by the first-time user. It's not a true tap-shift system because the driver can force the transmission to downshift with throttle input, but rather one that lets the driver manually block out the highest gears, say for descending a mountain grade.

There are two transfer cases on 4WD models: a traditional shift-on-the-fly Borg Warner 44-45 unit for Tradesman, Express, Outdoorsman, and SLT models, and a shift-on-demand Borg Warner 44-44 with an Auto 4WD setting, standard on V-8-powered Big Horn, Sport, Laramie, and Laramie Longhorn. The range select is via a large knob on the center stack above the driver's knee on Rams with 6-speed automatics, and done with somewhat smallish buttons under the rotary shifter knob when equipped with the new ZF 8-speed autobox. Both cases offer a 2.64:1 low-range ratio and selectable neutral position. Combined with the ultra-low 4.71:1 first of the new 8-speed automatic and 3.92:1 final drive of the 4x4 Outdoorsman, that gives off-roaders an effective 48.7:1 reduction for slow-crawling in first gear.

Ever more ambitious federal fuel-economy targets now provide the incentive for improved fuel efficiency. A new thermal management system addresses the problem of parasitic losses and sluggish shift performance of an automatic transmission in cold weather by warming transmission fluid in a heat-exchange unit with warm engine coolant. Another new technology called pulse-width modulation controls the fuel pump and cooling fan, running them only as much as needed, reducing the electrical load the charging system places on the engine. The Ram 1500's new electric power steering system works on the same principal, providing boost to reduce steering effort only to the degree that it's needed. EPS alone netted a 2 percent fuel economy improvement and eliminated a 5-hp drag on the engine from the previous hydraulic pump, which ran continuously whether steering boost was needed or not. The rack-mounted EPS does a good job of providing linear steering response with low friction and the on-center feel of a well-tuned hydraulic gear, something earlier electric steering systems in competitor vehicles lacked.

Another Ram fuel-economy enabler is weight reduction. The 2013 model uses more high-strength steel in the frame, saving up to 13 pounds in the process. Further, the new frame is stiffer, something that's immediately apparent by the reduced sound of flex and twisting when driving the new Ram over uneven terrain off-road. An aluminum hood, aluminum front lower control arms, and other weight-saving measures such as high-strength steel bed crossmembers also help get the mass out.

Already benchmarked by other truck makers for its comfortable ride as a result of its class-exclusive multi-link live axle coil-spring rear suspension, Ram ups the ante for 2013. Borrowing from lessons learned on the Jeep Grand Cherokee, air suspension is now available on the 2013 Ram pickup. It's optional on all Quad Cab and Crew Cab models, but not available on Regular Cabs, even those with R/T trim. Four air springs replace the coils in the front and rear suspension and cushion the ride, noticeably reducing impact harshness over ruts, bumps and uneven pavement.

This gem of a system has five modes and is controlled by a switch on the center stack. Left to its own devices, the truck stays at normal ride height until highway speeds are achieved, whereupon the air springs lower ride height just over an inch at highway speeds (60 mph) to improve aerodynamics and help improve fuel economy. Another feature of the air suspension is a kneel mode which can be manually selected to make passenger ingress and egress easier and ease the lifting of cargo into the bed. For off-road operation, ride height can be increased either 1.2 inches or 2 inches, which Chrysler claims gives the Ram 1500 class-leading ground clearance, breakover angle, and departure angle. No other full-size pickup has anything like it. In the quest for the best full-size pickup ride quality, payload capacity isn't sacrificed; Ram claims a credible 1930-lb payload capability.

One thing's for sure -- buyers and the things they carry or tow aren't getting any smaller, so there's a continuing need for trucks that have the space and power to get the job done. Chrysler has met the challenge, the same one that's facing all truck makers, to find a way to maintain the capabilities that full-size truck buyers want while meeting ever-tougher fuel economy requirements mandated by the U.S. government.