Everything You Wanted to Know About the Cummins 6.7L Diesel Engine

Countless drivers of RAM pickups have become familiar with the joys of owning a truck with the Cummins Diesel engine. These powerful units have been driving some of America’s most rugged and durable trucks for more than 30 years, a collaboration that started back when trucks were still produced under the Dodge label.  Even today, the relationship between RAM and Cummins still goes strong.

So, let’s look at the RAM Cummins engine, specifically the 6.7L Diesel engine, to find out more about what makes it tick in both the fourth and fifth generations of RAM pickup trucks.  This information is essential, whether you are just curious about the RAM Cummins combo or are shopping for a used RAM pickup truck,

About Cummins

Cummins was initially founded in 1919 as the Cummins Engine Company, but after 2001 restructured as simply Cummins. Headquartered in Columbus, Indiana, Cummins is a global company with operations as far afield as India and China. As it turns out, powerful Diesel engines like the Cummins 6.7L are welcome no matter what language you speak!

The founders were J. Irwin Miller, a local banker in Columbus, and mechanic Clessie Cummins for whom the engines and company are named. Even though their earliest Diesel engines were effective, the company didn’t find success until 1933 with the Model H, used in railroad equipment.

In addition to being the powerplants for RAM trucks, Cummins Diesels can also be found in heavy trucks, buses, and RVs.  These engines even power, marine craft, construction equipment, and Bradley fighting vehicles. Cummins engines are everywhere.  Dodge started using the engines back in 1989, the first of which was the 12V Cummins with 160 horsepower (HP) and 400 lb-ft of torque.

Right now, Cummins employs some 58,000 employees around the world and has been named among the Top 25 Most Responsible Companies in 2021 by Newsweek.  Even in the difficult times of 2020, Cummins reported $19.8 billion in revenue.

Cummins 6.7L Diesel Engine Specifications

Below are a few key standard specs for the Cummins 6.7L

Horsepower: 370 (max. 420 HP)

Torque: 850 lb-ft (max. 1075 lb-ft)

Cylinders: 6

Bore: 4.21 inches

Stroke: 4.88 inches

Alternator: 220 amps

Throttle: Electronically controlled

Net weight: 1,071 lbs

Fuel System: Bosch HPCR

Let’s take a closer at the Cummins 6.7L Diesel in RAM trucks.

RAM Cummins – Use of the Cummins 6.7L in Fourth-Generation RAM Trucks

The fourth generation of RAM trucks, launched in 2009, made use of the Cummins 6.7L Diesel engine:

2010-2012 RAM 2500 and 3500

2012 Ram 2500, Image By Motor Trend

In the early period of the fourth generation, Dodge customers wanting a bigger 2500 or 3500 truck had the choice of just two models that carried the impressive 6.7L. Others opted for the 1500 with smaller engine options or the 2500/3500, but with one of those Hemi V8 engines you might have heard about.

The 2010-2012 RAM 2500 and 3500 came with the standard output 6.7L, which delivered 350 HP and 650 lb-ft of torque. In mid-2011, however, these six-speed automatic transmission models could be equipped with an upgraded Cummins and a higher torque output of 800 lb-ft.

2013-2019 RAM 2500 and 3500

2019 ram 3500, Cummins Diesel Engine
2019 Ram 3500, Image by Motor Trend

By 2013, those seeking more 6.7L options got their wish with the 2013-2019 RAM 2500 and 3500 trucks that could be equipped with both manual and automatic transmissions.

The automatic models proved the most popular with torque-hungry gearheads, outputting up to 1000 lb-ft in the 2019 RAM 2500/3500 equipped with the 6.7L Cummins Diesel Aisin ASC69RC Automatic version.

The 68RFE (automatic only) version in 2019 was also potent, outputting 850 lb-ft of torque.

2010-2018 RAM Chassis Cab

Cummins Diesel Engine
Ram Chassis Cab, Image by Michael Simari, Car and Driver

Each of the two versions of the fourth-generation RAM 2500/3500 Chassis Cab was powered by a 6.7L Cummins diesel.

  • 2010-2012 model – used a standard Cummins 6.7L inline-six with 305 HP and 610 lb-ft torque
  • 2013-2018 had two choices: the six-speed manual (325 HP; 650 lb-ft torque) and the Aisin AS69RC automatic (325 HP; 750 lb-ft torque)

Check out this 2015 RAM Tradesman 4WD with Cummins Diesel

RAM Cummins Engine – Use of Cummins 6.7L in 5th-Generation RAM Trucks

Launched for the 2019 model year, the fifth-generation is the latest version of RAM trucks.  

The keyword for this fifth generation is “Heavy Duty,” as these models would continue with the 6.7L Cummins Diesel engine under the hood.

This applies to all RAM 2500, 3500, and 5500 models (Chassis Cab), but there is one exception. Anyone eyeing up the RAM 2500 Power Wagon needs to know that, unfortunately, the Cummins Diesel engine is not available. This RAM is only available with the gas-powered 6.4L V8 HEMI.

Here’s a rundown of models and trims in the fifth generation:

  • RAM 2500 – Tradesman, Big Horn and Laramie
  • RAM 3500 – Tradesman, Big Horn, Laramie, Limited Longhorn
  • RAM Chassis Cab – Tradesman, SLT, Laramie, Limited

Just before you sign your name on the dotted line for your very own RAM, you should know that in the fifth-generation models, the Cummins 6.7L Diesel is not always the standard engine option but rather the upgrade. Don’t assume there’s a Diesel under the hood.

RAM Cummins: What’s the Benefit?

To wrap up this exploration of RAM and Cummins, let’s reflect a little on why this 30-year partnership remains so strong.

First of all, no matter how much the world wants to electrify and move away from hydrocarbons, there’s just something so irresistible about a powerful turbo-diesel. They’re almost impossible to stall and, when properly maintained, can last almost forever.

Next, the torque and pull of these engines can never be paralleled by any gasoline or hybrid option…unless you cheat and pick some extreme sports car engine (but we’ll save the discussion about the RAM TRX for another occasion). The power of a Diesel is even more evident when hauling or towing heavy loads.  Not to mention, Diesel power is still well-suited for off-road driving or daily driver duty on ordinary streets and highway driving. These are the secrets of the RAM-Cummins partnership. Long may it continue.

Looking for a used RAM Cummins 2500 or another RAM Diesel model?   Then Explore Our Huge Selection of Used RAM Cummins pickup trucks for sale.  Please note that our inventory changes frequently and is subject to prior sale. Be sure to ask us about incoming used RAM Cummins models.

Buy a Used RAM Cummins Diesel at Trust Auto

Truck buyers from far and wide have discovered how easily used RAM Cummins shopping is at Trust Auto.  From our vast selection of RAM 1500, RAM 2500, and RAM 3500 trucks to our professional staff who are well-versed in all things Cummins Diesel, Trust Auto in Sykesville is the trusted choice for truck shoppers. 

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When your search calls for the best-used car dealership near me, Trust Auto is the answer. From Baltimore and beyond, we’re the used truck dealer that makes things easy. Call or stop by today to explore our extensive selection of high-quality vehicles.