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2002-2009 Dodge Ram Heavy Duty Engines

Cummins Diesels

The 2002-04 High Output Cummins Turbo Diesel was the most powerful diesel engine available in a full-size pickup, but was still very drivable through the full range. The engine had common-rail fuel injection; maximum torque came 400 rpm lower than the GM Duramax, and 100 rpm lower than the Ford PowerStroke.

The 5.9 liter engine was rated at 555 pound-feet of torque at 1,400 rpm and 305 horsepower at 2,900 rpm, delivering a class-leading trailer towing rating of 23,000 pounds (GCVWR). Nearly three quarters of all heavy duty Ram pickups were sold with diesels.

Cummins turbo diesel engineAn inline six, the Cummins had around 25% percent fewer parts than typical V-8 diesels. Oil drain/filter service intervals were doubled from 7,500 miles to 15,000 miles for schedule A service and from 3,750 miles to 7,500 miles for schedule B service.

The “standard” Cummins Turbo Diesel power rating went up from 235 hp to 250 horsepower at 2,900 rpm, with 460 pound-feet of torque at 1,400 rpm.

Both versions used a new high-pressure common rail fuel injection systems with pilot injection starting in the 2003 pickups. (Pilot injection sent a short burst of fuel before the main injection to cut spikes in combustion pressure; it reduced noise and improved cold starts.)

An electronically controlled, gear-driven fuel pump provided pressures up to 23,200 psi (1600 Bar) and was less dependent on engine speed than traditional systems. The fuel-injection calibration was refined for smoother, quieter combustion. Cold starting was verified at temperatures as low as -40° degrees Fahrenheit.

2005-06 Cummins diesel

The 2005 pickups were retuned for more diesel power, with both particulates and nitrogen oxides meeting meet 50-state standards. The combustion bowl and a high-flow, electronically-controlled-wastegate turbocharger matched boost pressure with demand; no exhaust gas recirculation was needed or used.  This version eliminated the need for “normal” and “high output” diesels, as in 2002-04.

Press materials referred to the engine has having either 600 or 610 pound feet of torque, starting at 1,600 rpm; the engine was rated at 325 hp, close to the gasoline V8

The Cummins turbodiesel boasted an average of 350,000 miles before an overhaul was needed. This was arranged with gallery-cooled aluminum pistons, Inconel® exhaust valves hitting high-cobalt Stellite® valve seats, a multi-layer gasket between head and exhaust manifold, and forged steel, fracture-split connecting rods.

2007 Cummins diesels

The 2007 Dodge Rams had a new 6.7 liter Cummins turbodiesel that met 2010 model-year standards, three years early. Coupled with the 68RFE six-speed automatic, it included a fluid-based emissions-reduction system to meet 50-state requirements, while increasing fuel economy by 20% to 40%; NOx emissions were slashed by up to 90% through an adsorber catalyst. Power ratings were 350 hp and up to 650 pound-feet of torque (manual transmission pickups were limited to 610).

Cooled exhaust gas recirculation (EGR) and variable geometry turbochargers helped performance and emissions; a self-cleaning filter and a catalyst slashed particulates by a factor of 10, while a closed crankcase ventilation system eliminated oil carry-over. Time-to-major overhaul intervals stayed at 350,000 miles, more than a 100,000-mile advantage over the competition. Nearly 40% of the new engine’s parts were carryover.

The price at launch was $33,650 including destination. Reliable source oh2o had predicted it exactly.

5.7-liter HEMI Magnum V-8

Dodge Ram - 5.7 Hemi engineThe 2003 Dodge Ram 2500 and 3500 heralded the return of one of the most legendary names in automotive lore: HEMI. The new 5.7-liter HEMI Magnum engine was the standard engine on the Dodge Ram Heavy Duty, producing a class-leading 345 horsepower at 5,400 rpm and 375 pound-feet of torque at 4,200 rpm. It provided best-in-class acceleration and towing capability against similar gasoline-powered trucks.

“We liked the elegance and simplicity of the HEMI design and it beats a dual overhead camshaft design in terms of torque and power for a heavy-duty truck,” said one engineering leader. “We think that the central camshaft, pushrod design is the optimal solution for vehicles with large mass designed to carry heavy loads.”

At some point, the Ram 3500 Hemi went down to 330 hp; but by 2009, it was up to 355 hp and 395 pound-feet on both the Ram 2500 and 3500.

Dodge Hemi 5.7 V8 engine

The Hemi had a composite integrated air/fuel module and electronic throttle control; the head design made room for larger, cross-flow valves, for better airflow. Compared with the old 360, it had lower emissions and an 8% gain in fuel efficiency.

The cast steel rocker arms actuated splayed valves. Willem Weertman had suggested two spark plugs per cylinder for faster combustion with lower emissions, which seemed to work out well. A new direct ignition system and fully-balanced, cast, nodular iron crankshaft running in cross-bolted steel main bearing caps completed the package.

The Hemi engine hooked up with the 545RE five-speed automatic or a manual transmission.


Available in 2002 was the original 8.0-liter, V-10 Magnum engine with 450 lb.-ft. of torque at 2,800 rpm, and, on the limited-edition SRT (later years), the 505 horsepower Viper version of that same V-10.

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