From Chrysler’s perspective, creating a great diesel engine in Europe was just the beginning of the process.

“We had to comply with U.S. OBD (on-board diagnostics) and emissions regulations that are different and are significantly more stringent than in Europe,” says Luis Cattani, chief engineer-Diesel Platforms.

“Then we had to balance the NVH, fuel economy and engine capabilities to give customers of this type of application the best value for their money. Lastly, we wanted to fit the engine and aftertreatment system in an already defined vehicle architecture,” Cattani says.

Another big challenge was the fear American consumers, unlike Europeans, simply would not accept a light-duty diesel, even in a pickup.

Chrysler’s U.S. pickup competitors decided not to take the risk. Ford, General Motors, Nissan and Toyota all cancelled programs for diesel-powered light-duty pickups in 2009 and 2010. Honda and Subaru pulled the plug on small diesels for cars and cross/utility vehicles in the U.S. as well.

Only German automakers, Mazda, GM (focusing on a 2.0L diesel for the Chevy Cruze) and Chrysler, which had merged with European automaker Fiat by then, moved ahead.

But all the worries dissipated immediately when the trucks finally went on sale. Between the afternoon of Feb. 7 and the morning of Feb. 10, Ram Truck received more than 8,000 EcoDiesel orders, which quickly filled the initial allocation for the powertrain, Chrysler says. Now there are concerns about demand outstripping supply.

Chrysler executives say they are not surprised by the smashing debut, pointing to the Ram’s 20/28 mpg (11.7-8.4 L/100 km) city/highway fuel economy, unsurpassed torque and up to 9,200 lbs. (4,173 kg) of towing capability. Fuel economy during WardsAuto testing approached 24 mpg (9.8 L/100 km), better than the truck’s official combined fuel economy of 23 mpg (10.2 L/100 km).

“When you drive the Ram 1500, it’s so quiet you don’t realize it has a diesel engine,” Cattani says. The truck has capability. Then you add the best fuel economy in a light-duty pickup and it sells itself.  The customer was ready for diesel.” 

So far, it’s difficult to discern what type of buyers are snapping up the trucks.

“The volume Ram 1500 EcoDiesel is a Crew Cab 4x4 in the Big Horn trim level, which is much the same as we see in our V-6 Pentastar 8-speed and V-8 Hemi 8-speed powertrain options. Over time, we're interested in seeing where the data will skew, but it's too early to say what the overall trend will be,” says Bob Hegbloom, director-Ram Truck Brand.

So this begs the question: Is diesel Chrysler’s answer to Ford’s pickup fuel-economy challenge?

Bob Lee, vice president and head of Engine, Powertrain and Electrified Propulsion Systems Engineering, does not see diesel as a single solution, but it clearly looks like a big piece of the response to Ford’s aluminium, and gasoline engine downsizing and turbocharging strategy.

“Diesel is one of many technologies which we believe can help in complying with the fuel-economy requirements now and through the journey to 2025,” he says. “One of the major benefits of the diesel is of course its fuel economy on standard drive cycles, but moreover it has superior fuel economy under real-world work conditions.

“Other benefits include the substantial customer ‘pull’ for the technology based on their experiences of ‘fun to drive,’ superior product longevity and value retention, especially through lease residuals,” Lee says.