By offering a diesel engine in its 2014 Ram 1500 pickup, Chrysler becomes the first OEM to bring 30-mpg (7.8 L/100 km) potential to the light-duty side of the U.S. full-size truck segment. The much-anticipated product action also will help move Chrysler’s fleet fuel efficiency closer to the 35.4-mpg (6.6 L/100 km) combined truck/car average required by U.S. CAFE standards for 2017.
Production of the Ram 1500 EcoDiesel model, powered by a VM Motori 3.0-L V6 turbodiesel and Chrysler 8-speed 8R70 automatic transmission, begins 3Q13. VM Motori is 50% owned by Chrysler parent Fiat SpA and 50% owned by General Motors.
In announcing the new diesel powertrain option Feb. 14, Chrysler claimed the truck will achieve best-in-class fuel efficiency and torque, but it did not release specific numbers. Currently the 2013 Ram 1500 with naturally aspirated 3.6-L V6 leads the segment with an EPA-rated 25 mpg (9.4 L/100 km).
“We’ve had this [VM Motori diesel] in our Ram forecast for the past year,” said Jeff Jowett, Manager of North American Powertrain analysis at IHS Automotive. “It looks to be a fantastic combination because many Ram customers are horse owners, landscapers, and tradespeople who pull trailers. Those customers often don’t need the big V8s of the heavy-duty trucks.”
The 3.0-L V6, part of VM Motori’s A630 family, also will be used in the U.S.-market 2014 Jeep Grand Cherokee and Chrysler 300, with the Jeep application rated at 240 hp (179 kW) and 420 lb•ft. The Ram application may have different calibration and SAE-certified outputs. Jowett and other powertrain experts who spoke with AEI expect the diesel Ram to be equipped with a selective-catalytic reduction (SCR)-based exhaust aftertreatment suite.
The engine is a DOHC 60° V6 with a compacted-graphite iron cylinder block and aluminum heads. Bore and stroke dimensions are 83 x 92 mm (3.27 x 3.62 in). The bore centers are spaced 96 mm (3.78 in). Overall dimensions are 695 mm (27.3 in) length, 729 mm (28.7 in) width, and 697.5 mm (27.4 in) height. Approximate fully dressed weight is 230 kg (507 lb).
The lower end features a bedplate that provides rigid support for the forged-steel crankshaft, secured by four-bolt main bearing caps. A structural two-piece aluminum oil pan helps reduce NVH. Oil jets in the crankcase provide cooling for the low-friction pistons, which ride on cast-iron con rods.
Each bank of twin overhead camshafts is driven by roller chain and operate four valves per cylinder through finger-type followers. The compression ratio of the Euro5-compliant 3.0-L diesel used in European Jeep applications is 16.5:1. The European version uses Fiat’s MultiJet II direct fuel injection, which is capable of eight injections per combustion cycle, and a single Garrett VGT 2056 variable-geometry turbocharger with air-to-air intercooler. The integral exhaust gas recirculation loop is liquid-cooled. Chrysler has not announced specific calibrations, hardware specifications, and SAE engine ratings for the 2014 Ram EcoDiesel application.
The diesel V6 adds a new dimension to the many significant vehicle-efficiency technologies designed into the Ram 1500 for the 2013 model year. Those assets—active grill shutters, active-leveling suspension, stop-start, active powertrain thermal management, and various aerodynamic improvements—helped the Ram move to the head of its segment in terms of fuel efficiency and score major awards including 2013 North American Truck of the Year. That combination of diesel and vehicle technologies leads experts to believe the diesel Ram could be first in its segment to crack the 30-mpg barrier.