Written By, Mike McGlothlin
Cummins 6.7L
Bigger Displacement, More Power, Cleaner Emissions
Born out of the need to meet stricter emission standards set forth by the EPA, Cummins designed the 6.7L to replace the outgoing (“pre-emissions”) common-rail 5.9L. The Cummins 6.7L ISBe was introduced in 2007 and debuted in 2007.5 model year Dodge Ram heavy duty pickup trucks. It would be the first time EGR and DPF emissions technology made its way onto the diesel engine found in Ram trucks. Like the 5.9L, it utilized a parent bore, cast-iron block, but the Cummins 6.7 L engine employed a siamese cylinder bore design for improved strength. Its larger displacement also allowed for more torque and horsepower production. When it was released, the original Ram-intended Cummins 6.7L turned out 350 hp and 650 lb-ft, figures that helped define early 6.7 L Cummins horsepower expectations in the heavy duty pickup segment.
Common Applications
While it’s best known for its presence in Ram trucks (2500/3500 series, as well as 3500/4500/5500 cab-and-chassis configurations), the Cummins 6.7L serves duty in countless other applications. Among them are the usual suspects: medium duty trucks, school buses, motorhomes, emergency vehicles, gen-sets, construction and agriculture equipment, marine vessels, and even well servicing. In select medium duty vehicle applications, the Cummins 6.7L is badged as a PACCAR PX-7. The 6.7L Cummins has even been called upon by the U.S. military for use in the RG-31 series MRAP, further highlighting the engine’s versatility beyond standard cummins 6.7 engine specs found in consumer truck platforms.
A Production Run In The Millions
Without question, the highest demand for Cummins’ 6.7L power plant comes from Stellantis North America, parent company of Ram Trucks. For Ram applications alone, Cummins has produced more than 3 million engines (5.9L and 6.7L included) since 1988. In 2012, the 2 millionth engine rolled off the assembly line at the Columbus Midrange Engine Plant (CMEP). Less than seven years later (2019), engine number 3 million was produced. With demand for the Cummins engine option continuing to top 150,000 trucks annually, expect that figure to top 4 million units any day now. Worldwide, and across all of the segments the Cummins 6.7L can be found in, the overall production numbers for this engine is well over 2.5 million.
Why It Will Remain In High Demand
The Cummins 6.7L is generally reliable aside from the intermittent emissions equipment problems all modern diesel engines face. But despite the regularity of emissions-related component failure (namely today’s extensively complex and sensitive exhaust aftertreatment systems), the core of the 6.7L engine remains robust, durable, and efficient. It’s also the cleanest running power plant in this displacement range that Cummins has ever produced—as well as being its most powerful. Combined with proven cummins 6.7 engine specs and continued improvements in 6.7 L Cummins horsepower across model years, the platform remains highly desirable. And thanks to its production volume totaling millions of units, parts availability (both OEM and aftermarket) is extremely high, with core blocks, heads, and rotating assembly components being easy to source.
Sources:
Big Bear Engine Company
https://www.4btengines.com/cummins-6-7l-rebuilt-engines/
Green Handle Media
https://greenhandlemedia.com/2023/06/2007-5-2023-6-7l-cummins/
2019 Forecast for Class 6-7 engines
