Westlake Village, California -- Adding to its amazement factor for 2014, the Ram 1500 now offers buyers the choice of a brawler or a bruiser. The brawler, of course, is the available Hemi V-8. Raise it off idle, and you know it has attitude. To delve hard through its midrange toward the top is to experience true bellicosity.
Now there's the bruiser: the Ram 1500 EcoDiesel. This engine is nothing but punches to the midsection. You know this merely by listening to it. While an unstinting effort was made to suppress the rumble that's the bellwether of diesels, we didn't mistake the grumbling exhaust note for the tones of a carillon. The clattery percussiveness is censored remarkably well, but it isn't silenced.
In a shrewd move, Ram is introducing this 3.0-liter turbodiesel V-6 to the light-duty pickup class. Ram led off with Cummins turbodiesel sixes in its heavy-duty trucks in 1989, and others followed in that category. Being first to market with a light-duty diesel will have advantages as other manufacturers jump in. Nissan will insert a Cummins V-8 into the Titan, and diesel power is slated for GM's midsize trucks as well.
The Ram's DOHC engine, which is approved for sale in all fifty states, is available in six of nine models. When the final fuel-economy figures come in, the V-6 could redefine efficient pickup performance. It wrings out 240 hp at 3600 rpm but, more significantly, 420 lb-ft of torque at 2000 rpm. (When the Cummins turbodiesel six was adopted, it produced 400 lb-ft.)
The Hemi V-8 far surpasses the turbodiesel V-6 in power, at 395 hp, which would be useful if you were trying for the household haulers' class record at the Bonneville Salt Flats. But for towing up to 10,000 pounds, plowing heavy snow, or carrying up to a 1630-pound payload, the torque is nice to have. With nearly twice the displacement, the gasoline-fueled V-8 languidly churns out 410 lb-ft of torque at 3950 rpm. Meanwhile, the diesel should easily surpass the 25 mpg highway achieved by the gasoline 3.6-liter V-6 -- the Ram's other available engine -- while also offering less consumption under load and extending the truck's range to previously unachieved distances.
From Italy, with Love
The 60-degree, 24-valve DOHC V-6 is designed and made by VM Motori in Cento, Italy. Since 1992, VM Motori has supplied diesels for Chrysler's European products, such as the Jeep Grand Cherokee and the Chrysler 300. This engine is nearly identical to the one now offered domestically in the Grand Cherokee; the only differences are that the Ram's all-aluminum oil pan and oil cooler have been modified for packaging considerations, according to powertrain engineering chief Jamie Standring.
Fuel is delivered under 29,000 psi of pressure to the six cylinders by a common-rail injection system. Relying on boosted induction from a variable-geometry turbocharger, the V-6 operates with a 16.5:1 compression ratio, significantly higher than the typical gas engine, and it's designed accordingly, with a block and bedplate of compacted graphite iron. This is just one of several strategies to quell NVH. Uniform dispersal of the graphite produces several desirable properties, Standring said, speaking in the soft brogue of his native English Midlands.
"The graphite in the cast iron gives the material a higher strength," he said. "So you can basically use that strength to create a stiffer structure. In terms of diesels and noise, the key is ensuring that the higher combustion loads are managed in that structure. You need a stiffer bottom end of the engine to make sure you don't end up with a noisy powertrain."
We had Standring explain why a diesel produces so much torque. He attributed it to "the higher calorific value in the fuel, higher compression ratios, and the turbocharging." The high compression ratio is due to the fact that diesel fuel has less combustibility. "It's less likely to ignite as you compress it. And you're relying on compression to ignite it. The higher compression ratios drive the fuel-air mix up to a higher temperature so it does ignite."
Applying the "Eco" to the "Diesel" meant emulating the European luxury sedans, as well as heavy-duty Class 8 trucks, and injecting a solution containing urea into the exhaust stream. "It's an iteration where we've changed the emissions after-treatment from diesel particulate filter and oxidation cat[alyst] only to SCR: Selective Catalytic Reduction, the urea system."
An eight-gallon tank holds a mixture of deionized water with urea in a 32.5 percent solution. (The EcoDiesel will keep running at full power when the solution runs low.) This liquid is pumped into the stream just behind the diesel particulate filter, and oxides of nitrogen are reduced.
The storage tank, whose nozzle is beside the fuel filler, is scheduled for replenishing at the same 10,000-mile interval that oil changes are due. Word on the Web is to take care of this yourself and purchase the solution at a truck stop instead of letting a dealership charge a small fortune for this mythical, magical fluid.
But is the question settled?
The lack of any highway driving hampered our evaluation of the 1500 EcoDiesel. Twisting around on Mulholland Highway in the Santa Monica Mountains and dropping down to the Pacific Coast Highway hardly revealed all the engine's dynamic characteristics. It was laudably quiet and smooth-running but a bit hesitant to respond when we kicked down a gear in the eight-speed automatic. Otherwise, there's not much news. It's all very civilized and refined, and it's so quiet that we thought we could hear surfboards slapping the water at beaches along the Pacific Coast Highway.
Diesels in general strike us as being rather blunt and impersonal, and the EcoDiesel is no different. On the other hand, the Hemi V-8 is like an affectionate uncle who tells great stories. But you want to get the job done, right? We observed around 17 mpg while crawling up and down the mountainsides.
Like most of the diesels we’ve seen in light vehicles, you pay a price premium. The Ram 1500 EcoDiesel costs $2850 more than the Hemi V-8. So the question arises, where is the break-even point? We’re waiting for the final fuel-economy figures before the EcoDiesel-equipped models go on sale in December. But after our test, we’re still inclined to go with the Hemi V-8. It’s that good.
2014 Ram 1500 EcoDiesel
|Base Price Range:||$30,000-$55,000|
|On Sale:||December 2013|
|Engine:||3.0-liter DOHC turbodiesel V-6|
|Horsepower:||240 @ 3600 rpm|
|Torque:||420 lb-ft @ 2000 rpm|
|Curb Weight:||6105 lb|