Three-liter diesel in a Ram 1500: The first diesel in a full-size pickup

3.0-liter EcoDiesel V-6 engine

3.0-liter EcoDiesel V-6 engine

The 2014 Ram 1500 with the 3.0-liter EcoDiesel could be considered the first full-size pickup with a diesel engine. Or it could be considered the first diesel in a full-size pickup.

That’s not a tautology. There is a difference. The latter is an engine with a truck around it. And it’s a great truck, as we noted in our review. But we thought the engine deserved a closer look.

The three-liter diesel is actually not a product of the Chrysler Group but rather VM Motori, an Italian diesel engine specialist that’s been supplying engines to Chrysler since 1992.

The engine, as noted above, is a three liter, a 60-degree V-6, with dual-overhead-cams and four valves per cylinder and it’s rated at 240 horsepower at 3,600 rpm and trailer-towing 420 lb.-ft. at 2,000 rpm.

To provide a rugged basis for the 3.0-liter EcoDiesel as well as reduce vibration, noise and harshness, the engine block and bedplate are constructed of compacted graphite iron, or CGI, with the graphite in it distributed more evenly. A structural aluminum oil pan adds stiffness.

The cylinder heads are made from aluminum, heat-treated and with individual bearing caps to reduce friction and further reduce NVH.

The crankshaft and connecting rods are made from forged steel, the pistons from aluminum alloy, chosen to reduce reciprocating mass in the engine, improving efficiency and what Ram calls “performance feel.” Oil jets directed at the bottom of the pistons help control piston temperatures,

The fuel delivery system uses Fiat’s MultiJet II common-rail injection system with 29,000 psi line pressure. High-dispersion nozzles and a new servovalve allow up to eight times per cylinder cycle with greater precision. The system has improved interval control between two consecutive injections, which reduces fuel consumption and improves emissions via improved injection timing and better fuel distribution in the combustion chamber.

On the backside of engine operation is a state-of-the-art selective catalytic reduction to decrease exhaust emissions, using a Diesel Exhaust Fluid system. The system reduces both NOx emissions, the big hurdle for clean diesel exhaust.

The Diesel Exhaust Fluid, or DEF, is a urea solution similar to AdBlue used by certain German manufacturers. The DEF works with the Selective Catalytic Reduction System to reduce NOx, along with specific improvements to decrease DEF buildup in the system. Soot trapped in the exhaust is periodically burned off in a way that doesn’t increase particulate emissions while also improving fuel economy.

The system includes an insulated DEF tank with heated lines to mitigate the effects of cold-weather starting, plus a passive cooling system which doesn’t require engine coolant for the DEF injectors.

The DEF tank holds eight gallons of fluid, and while how the truck is operated determines how frequently the tank must be refilled, typical refill is required about every 10,000 miles. The filler for DEF is under the fuel door, making it easy for owners to refill the tank with DEF fluid, which is available over the parts counter at Mopar and Chrysler Group dealerships and at Cummins dealers and distributors.

The engine has a standard oil cooler, and if the prescribed 5W30 synthetic oil is used, the engine oil has a 10,000 mile replacement interval, making it possible to refill the DEF tank during an oil change. The instrument panel has a DEF gauge, similar to that of a fuel gauge, so the driver knows how much DEF remains in the tank. The 3.0-liter EcoDiesel is the only engine with an exhaust urea injection system with a gauge. Everybody else wants you to return to your dealer to find out.

For fuel, the 3.0-liter EcoDiesel runs on standard ultra-low sulfur fuel, the stuff at the corner gas station, but for for those with a source, B-20 biodiesel can be used.

However, while the 3.0-liter EcoDiesel is the first diesel engine in a full-size pickup—Jeep also uses it in the Grand Cherokee, don’t expect it to be an only for very long. General Motors is said to be mulling dusting off the stillborn 4.5-liter Duramax V-8 that had been slated for the GMC Sierra and Chevrolet Silverado before GM went into quasi-bankruptcy, and the all-new 2015 GMC Canyon and 2015 Chevrolet Colorado midsize trucks will have four-cylinder 2.8-liter Duramax diesel engine power come next year. Nissan showed a Cummins 2.8-liter four-cylinder diesel in a Frontier pickup truck concept that was really more of a tease of what’s coming. There’s more in the works, though no one is necessarily talking. Just don’t expect the 3.0-liter EcoDiesel to be the last in the less-than-heavy duty pickup to have diesel power.

(Note: Yes, we know Volkswagen sole a pickup version of the Rabbit here in the early ‘80s, but that’s history. We’re looking, at least at the moment at the here and now).