Heavy-duty diesel pickups are the true workhorses of America, with engines making as much as 800 pound-feet of torque and the might to tow an entire fleet of B-Spec racers to the track at once.
Until recently, the towing capabilities that manufacturers claimed for each model were largely conjured up independently in a very public game of chest-pounding one-upmanship. But the Society of Automotive Engineers has lent newfound conformity to towing numbers with the creation of its J2807 recommended practice, already adopted by the players here. SAE J2807 adds credibility to tow ratings by clearly defining the procedures used to determine them.
The key element of J2807’s various tow-vehicle acceleration and climbing requirements, which the SAE modeled on real-world roads, is the so-called Davis Dam test, an 11.4-mile ascent near the dam on the Arizona-Nevada border. Here, a truck has to climb 3000 feet without dropping below 40 mph. Averaging a five-percent grade on Arizona’s Highway 68, the desolate mountain route combines challenging inclines with scenic vistas of the Colorado River, the Davis Dam itself, and the snowbird gambling retreat of Laughlin, Nevada. Along with the surrounding desert roads, it’s the perfect setting for evaluating the latest crop of modern-day draft horses.
The top-spec rigs on these pages start at about $50,000 in four-door, four-wheel-drive luxury trim and, with diesel engines and all the extras, surpass the base price of an Audi A7 luxohatch. More than just work trucks, these overachieving cowboy Cadillacs embody the bigger-is-better ethos, heaping on extra helpings of attitude for their devoted followers. The stakes here are high, the bragging rights incalculable.
Last year saw a wholesale update of the segment, with General Motors reinventing the dirty bits of the Chevrolet Silverado (and GMC Sierra), including a stronger, boxed frame and fortified underpinnings, as well as revisions to the Allison six-speed automatic ($1200) and the 6.6-liter Duramax V-8 turbo-diesel ($7195), now good for 397 horsepower and 765 pound-feet of torque.
Not by coincidence, Ford gave its nearly four-ton F-series Super Duty a new 6.7-liter Power Stroke diesel V-8. That engine—a $7835 option (along with its six-speed automatic)—features a lighter, compacted-graphite-iron block, outboard intake ports, and a novel twin-compressor-wheel turbocharger in the cylinder valley. An even 400 horsepower and 800 pound-feet are the results. Ford also modified the frame, suspension, and steering, and fitted a new chrome face bearing a blue oval that may or may not have started life as a serving platter.
Chrysler, to keep up, also boosted the torque of the venerable 350-hp, 6.7-liter Cummins diesel inline-six ($7195) in its big Ram trucks to 800 pound-feet in late 2011. Featuring an upgraded six-speed automatic ($1100), it is the only powertrain here to use an NOx adsorber rather than urea injection in its exhaust to meet current federal emissions regulations.
To make the trucks actually break a sweat, we enlisted the help of Titan Trailers of Waterville, Kansas, which graciously
supplied us with three tandem-axle, hydraulic dump trailers. We then loaded them with crushed rock for a gross trailer weight of 12,000 pounds each.
Hitching up was easy with the trucks’ integrated trailer-brake controllers and rearview cameras, so we hit the Davis Dam, the open desert, and Las Vegas Motor Speedway to see which pulled best.
Having two fewer cylinders and the lowest tow rating (12,000 pounds) from a conventional frame-mounted hitch (these trucks can handle much more with a fifth-wheel hookup in the bed) put the enormous Ram Mega Cab at a disadvantage. Whereas the Ford and Chevy were barely fazed by their trailers’ weight, the Ram’s Cummins six would occasionally groan under the load and labor to accelerate on steep grades.
The 7950-pound Ram’s 8.5-second run to 60 mph and its 16.7 in the quarter-mile were each more than a half-second off the pace of the second-quickest Ford. To see how the rigs performed when caned, we repeated acceleration tests with the trailers attached, and the Ram again trailed the Ford, by 0.9 and 0.4 second, respectively.
The Ram also brought up the rear in observed fuel economy over 600 miles (9 mpg with the trailer, 12 without) and lateral grip (0.68 g), and it elicited moans from test drivers for its slow, cumbersome steering, stiff ride, and the occasional harsh shift.
But the Ram is unfailingly honest about its mission. “It sounds like it belongs at a truck stop,” noted senior editor Tony Quiroga. “The other two seem to hide their diesel sounds like they’re ashamed of their truckishness. Not the Ram.”
Despite being quieter than previous examples and generating the same 67 decibels as the Ford Super Duty at a 70-mph cruise, the Ram’s noise levels at idle (50 dBA) and wide-open throttle (72 dBA) were each several ticks higher than the muffled Ford’s and noticeably louder than the Chevy’s. It made all the classic diesel sounds, too, including an authentic Class 8 truck growl with the exhaust brake at work. Depending on how much you embrace the rest of the truck’s over-the-top vibe, the experience can be either grating or enticing.
The Mega Cab Ram’s comfort and convenience, however, were universally praised, from its limo-sized cabin (despite oddly low official interior measurements) to its Laramie Longhorn saddle-leather seats with a reclining rear bench. The Ram also brings great ergonomics and storage, including the handy RamBox bed compartments ($1295). Country-western detailing abounds, but we could live without the decorative filigrees and buckles on the seatbacks. Your fondness for the Ram’s interior will exist in direct proportion to the size of your belt buckle.
Despite feeling strained at times by the heavy load, the Ram revealed strengths in other performance metrics. The brakes hauled this truck-and-trailer rig down from 70 mph in a best-of-test 315 feet. And the effectiveness of the exhaust brake and the transmission’s tow-haul mode meant that we rarely had to tap the brake pedal to maintain a safe speed down the steep descents near the Davis Dam.
Fans of the Cummins and long-haul luxury will find the Ram more than satisfactory, but it needs more muscle under the hood to excel in this company.
The first thing we noticed about the Ford F-250 was its quietness. In fact, this diesel monster is more hushed at a 70-mph cruise and wide-open throttle than the last Lexus ES350 we tested.
Our second observation was how strong the F-250 King Ranch felt on the move. Under full boost, the 7950-pound Ford repeatedly blasted up the grades on par with the Chevy.
The numbers tell the story, with the 340-pound-lighter Silverado consistently ahead at 60 mph and the more powerful Super Duty narrowing the gap considerably by the quarter-mile mark—both with and without the six-ton trailer along for the ride. In 30-to-50-mph and 50-to-70-mph acceleration, the two came in dead even at 3.9 and 5.1 seconds, respectively.
Backing the new Power Stroke V-8 is a revised TorqShift six-speed automatic and an exhaust brake that engages only when the tow-haul mode is activated (the Silverado and the Ram have dedicated dash buttons to enable exhaust braking). The transmission works well: It holds the proper gear while climbing and helps to slow the truck’s mass on downgrades. However, we noticed we had to apply the brakes often on descents to keep a steady speed.
The towering Ford impressed us by returning the best skidpad figure (0.73 g) at the track and tying the Chevy for fuel efficiency at 15 mpg unloaded, 10 mpg with the trailer. It required, however, a shocking 242 feet to stop from 70 mph. That’s two truck lengths plus about six feet longer than the Chevy. Not good. And that’s before we hooked up the trailer.
The rest of the truck exhibited a solid balance of capabilities, including the best visibility, the lowest tailgate height, and the only bed with a retractable step ($375), a grab handle, and a factory-installed fifth-wheel mounting accommodation ($370).
Inside, there’s ample storage, a comprehensive information screen in the cluster, and enough rear-seat space for three Carhartt-clad roughnecks. Our full-fancy test example, with its King Ranch package ($4765) plus the King Ranch package with Chrome ($695), had enough open-range glitz and cowhide to almost justify its near-$65,000 asking price, the highest in the test. Noticeably absent was a navigation system, which would have added a larger monitor for the rearview camera and another $1875 to the sticker.
The F-250’s overall blend of grunt, civility, and usefulness indeed deserves a tip of the old Stetson, but it wasn’t enough for top honors.
None of these trucks is remotely sporty, but the Silverado was clearly the most energetic of the group. At 7610 pounds, the Chevy was significantly lighter than the two others and was the easiest to maneuver in tight quarters. Plus, it offered the best ingress and egress. The Duramax V-8 and the Allison six-speed automatic transmission worked together to amazing effect, never seeming out of breath or in the wrong gear on grades.
One of the quickest GM diesel trucks we’ve sampled, the Silverado walked away in the unloaded-acceleration tests, hitting 60 mph in a carlike 7.1 seconds and the quarter in 15.7 at 89 mph. Those figures grew to 15.0 and 20.3 seconds, respectively, with the trailer attached, but the second-quickest Ford was still in the Silverado’s mirrors.
In the mountains, the Duramax always had power in reserve, as well as the best transmission programming and exhaust-brake setup for controlled descents sans wheel brakes. It was, however, the only truck to exhibit any untoward bucking movements from the trailer’s inertia.
The Silverado was also the only truck to pull a sub-200-foot stop from 70 mph (196 feet), and it teetered through the slalom more quickly than the others, at almost 40 mph. It was aided in this endeavor by the quickest and most responsive steering, as well as the only independent front suspension. Stopping prowess from 70 mph with the load (325 feet) and overall noise levels were midpack, and it tied the big Ford for best fuel economy.
Where the Chevy disappointed was in the area not addressed by the most recent update, namely the cabin, which has changed little since its 2006 debut. “This would be a cheap interior in a $30,000 truck,” noted one test driver. Compared with the others’ opulent fittings, the Silverado was a dismal place to sit: an expanse of chintzy, dark plastic; the least comfortable front seats; and the tightest rear quarters. While it was the only truck here with a back seat that folds up to make a flat load floor, it received additional demerits for a lack of clever storage, as well as a comparably small, low-res information screen in the gauge cluster. A detailed touch-screen navigation system ($2250) was its primary saving grace.
But those shortcomings didn’t overshadow the truck’s great drivability and pure brute strength. Moreover, the Silverado carried the lowest base and as-tested prices by a couple of grand and the least flash, which is nice if you happen to be put off by the rhinestone glint of the other trucks.
Given each brand’s historically loyal tribes, most buyers will make up their minds regardless of how things play out on paper. And the segment’s fierce competitiveness won’t let one player get too far ahead for too long. But right now, in this class of high-end haulers, the Silverado gets our nod for the best of what matters.
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