6.7L Cummins ISB Turbodiesel

6.7L Cummins Specs, Info, & Resources

The 6.7L Cummins is the latest of the B-series engine family, introduced mid-model year in 2007. Replacement of the previous 5.9L ISB was necessitated as the result of stricter Federal emission standards and the need for a more competitive platform to permit future growth under growing industry constraints. It is the first Cummins to require a diesel particulate (DPF) system, which captures more than 90 percent of soot from the exhaust stream and cleans itself through a process known industry wide as “regeneration”. For the 2019 model year, the revised 6.7L Cummins set an industry record by reaching the 1,000 lb-ft benchmark in torque output.

6.7L Cummins Diesel Specs

Production Years:

2007.5 - current

Configuration:

Inline 6 cylinder

B10 Life:

250,000 miles (~400,000 km)

B50 Life:

350,000 miles (~560,000 km)

Displacement:

408 cubic inches, 6.7 liters

Bore:

4.21 in (107 mm)

Stroke:

4.88 in (124 mm)

Cylinder Head Material:

Cast iron

Engine Block Material:

2007 - 2018

Gray cast iron

2019 +

Compacted graphite iron (CGI)

Firing Order:

1-5-3-6-2-4

Compression Ratio:

2007 - 2018

17.3 : 1

2019+ Std Output

19.0 : 1

2019+ High Output

16.2 : 1

Injection:

2007 - 2018

Direct injection, electronically controlled Bosch CP3 high pressure common rail, 26,000 psi max injection pressure

2019+

Direct injection, electronically controlled Bosch CP4.2 high pressure common rail, 29,000 psi max injection pressure

Aspiration:

2007 - 2018

Holset HE351VE variable geometry turbocharger (VGT), integrated exhaust brake function, air-to-air intercooler

2019+

Holset variable geometry turbocharger (VGT, model to be confirmed), air-to-air intercooler

Valvetrain:

2007 - 2018

OHV, 4 valves per cylinder, solid roller lifters, cam-in-block

2019+

OHV, 4 valves per cylinder, hydraulic lifters, cam-in-block

Reciprocating assembly:

2007 - 2018

Cast aluminum pistons, powdered metal connecting rods

2019+

Cast aluminum pistons, forged alloy steel connecting rods

Weight:

2007 - 2018

~1,120 lbs dry

2019+

~ 1,060 lbs dry

Oil Capacity:

2007 - 2018

12 U.S. qts w/ filter

2019

To be confirmed

Fuel:

ULSD; 2007 - 2013 models are B5 Biodiesel compatible, 2013.5+ models are B20 biodiesel compatible

Governed Speed:

• 3,013 rpm (2007 - 2012)
• 3,000 rpm (2013+)

Horsepower:

350 - 400 hp, see chart below

Torque:

610 - 1,000 lb-ft, see chart below

Dimensions:

Length

Width

Height

41.7"

28.6"

37.8"

6.7L Cummins Horsepower & Torque by Model Year

Note - ratings correspond to the factory advertised horsepower and torque in Dodge Ram pickups only.
Chassis cab and other commercial vehicle ratings may vary.

Model Year

Rated Horsepower

Rated Torque

2007 - 2010

350 hp @ 3,013 rpm

• 650 lb-ft @ 1,500 rpm (auto trans)
• 610 lb-ft @ 1,500 rpm (manual trans)

2011 - 2012*

350 hp @ 3,013 rpm

• 800 lb-ft @ 1,600 rpm (auto trans)
• 610 lb-ft @ 1,500 rpm (manual trans)

2013 - 2014

• 350 hp @ 2,800 rpm
• 370 hp @ 2,800 rpm
• 385 hp @ 2,800 rpm

• 660 lb-ft @ 1,500 rpm (manual trans)
• 800 lb-ft @ 1,700 rpm (68RFE trans)
• 850 lb-ft @ 1,700 rpm (Aisin AS69RC trans, 3500 only)

2015

• 350 hp @ 2,800 rpm
• 370 hp @ 2,800 rpm
• 385 hp @ 2,800 rpm

• 660 lb-ft @ 1,500 rpm (manual trans)
• 800 lb-ft @ 1,700 rpm (68RFE trans)
• 865 lb-ft @ 1,700 rpm (Aisin AS69RC trans, 3500 only)

2016 - 2017

• 350 hp @ 2,800 rpm
• 370 hp @ 2,800 rpm
• 385 hp @ 2,800 rpm

• 660 lb-ft @ 1,500 rpm (manual trans)
• 800 lb-ft @ 1,700 rpm (68RFE trans)
• 900 lb-ft @1,700 rpm (Aisin AS69RC trans, 3500 only)

2018

• 350 hp @ 2,800 rpm
• 370 hp @ 2,800 rpm
• 385 hp @ 2,800 rpm

• 660 lb-ft @ 1,500 rpm (manual trans)
• 800 lb-ft @ 1,700 rpm (68RFE trans)
• 930 lb-ft @1,700 rpm (Aisin AS69RC trans, 3500 only)

2019

• 350 hp @ 2,800 rpm
• 370 hp @ 2,800 rpm
• 400 hp @ 2,800 rpm

• 660 lb-ft @ 1,500 rpm (manual trans)
• 850 lb-ft @ 1,700 rpm (68RFE trans)
• 1,000 lb-ft @1,800 rpm (Aisin AS69RC trans, 3500 only)

*Beginning Feb 2011, some early model year 2011 trucks may have 2010 power/torque rating.

6.7L Cummins Model Year Changes

MY

Notable Changes Over Previous Model Year

2007.5

The 6.7 is introduced with a diesel particulate filter. In response to the profuse number of DPF clogging complaints, several new calibrations are rolled out via PCM re-flashes in an attempt to alleviate the issue.

2008

No significant changes over the 2007.5 model year engine.

2009

An access port is added to the turbine housing of the Holset turbocharger in order to permit cleaning of the VGT vanes. A new fuel filter housing using a dual-element style filter replaces the previous design. The new housing can be retrofitted to previous engines and captures finer particles than the single filter system. In addition, the engine receives a new water inlet housing design and coolant hose/fittings for the EGR cooler.

2010

A single, engine mounted PCM is installed that controls both the engine and transmission (for automatic trucks) - previous models used a separate unit for the engine and transmission. The fuel filter housing is revised once again, now featuring a 1/4 turn drain valve on the side of the housing. A 200 °F thermostat becomes the new standard, a slightly higher operating temperature than (and not compatible with) previous model years.

2011

Selective catalytic reduction (SCR, requiring the use of DEF/urea) becomes standard on chassis cab trucks. Torque is increased for automatic equipped trucks via a new engine calibration. Torque for manual transmission trucks and horsepower for all trucks remains unchanged.

2012

No significant changes over the 2011 model year engine.

2013

Torque is increased by 50 lb-ft for manual transmission trucks. Horsepower and torque are increased for automatic equipped trucks. A High Output variant of the engine is available in Ram 3500 models, backed by an Aisin automatic transmission. See Horsepower/Torque chart above for details. Selective catalytic reduction (SCR requiring DEF) introduced to all Cummins equipped pickups.

2014

No significant changes over the 2013 model year engine.

2015

No significant changes over the 2014 model year engine.

2016

Engine recalibration, torque increased from 865 to 900 lb-ft.

2017

No significant changes over the 2016 model year engine.

2018

Torque increased from 900 lb-ft to 930 lb-ft for H.O. Cummins, only available in Ram 3500 models with Aisin automatic transmission.

2019

Output on H.O. Cummins increased to 400 horsepower, 1,000 ft-lbs (Ram 3500 w/ Aisin transmission only). Standard Cummins torque increased to 850 lb-ft (w/ 68RFE transmission). Engine improvements include compacted graphite iron (CGI) engine block, revised camshaft, revised cylinder heads with new exhaust valves, springs, rocker arms. See sub-article below for full details.

Ram chassis cab models equipped with the 6.7L Cummins were detuned to 305 hp @ 2,900 rpm and 610 lb-ft @ 1,600 rpm through the 2012 model year, with a governed speed of 2,900 rpm. 2013+ chassis cabs got a more powerful 325 hp @ 2,400 rpm, 750 lb-ft @ 1,600 rpm engine with a 3,000 rpm governed speed. Detuning is common in commercial applications to maximize fuel economy and longevity at the expense of unnecessary power. Chassis cab models began requiring DEF (diesel exhaust fluid) for the 2011 model year, while standard pickups with the 6.7L Cummins did not utilize a SCR (selective catalytic reduction) system until the 2013 model year.

A High Output (H.O.) variant of the 6.7L Cummins was released for the Spring of 2011. Torque was increased from 650 lb-ft to 800 lb-ft while the rated horsepower was left unchanged. The H.O. Cummins was only made available for trucks equipped with the 68RFE automatic transmission, and therefore the output for manual transmission versions of the engine remained at 610 lb-ft.

2013 saw yet another push in performance, introducing a total of three variations of the 6.7L Cummins for Ram pickups. The first variation was limited to manual transmission equipped trucks - coupled to the G56 6 speed manual, engine torque was increased to 660 lb-ft (from 610) while horsepower remained unaltered. A second variation, offered in 3/4 and 1 ton Ram pickups and only available coupled to the 68RFE automatic transmission, saw output increase to 370 horsepower and 800 lb-ft. The High Output Cummins, which produced 385 hp and 850 lb-ft of torque, was only available coupled to the Aisin AS69RC automatic transmission and was only available in 1 ton Ram pickups (Ram 3500 models). In addition to these new offerings, SCR (selective catalytic reduction) w/ DEF injection became standard on all 6.7L Cummins. Ram Trucks reported an approximate 10% increase in fuel economy with the new engine lineup utilizing this exhaust aftertreatment technology. To reach and safely maintain these power levels, trucks also received dual transmission coolers, dual radiators, a higher efficiency intercooler (charge-air-cooler), larger capacity EGR system, and a higher efficiency mechanical fan. To increase effectiveness, the VGT exhaust brake system was also enhanced for the revised 2013 6.7L Cummins.

For 2015, the High Output model of the 6.7L Cummins saw torque increased from 850 lb-ft to 865 lb-ft. Though the increase was marginal, it granted Ram Trucks a marketing edge over their nearest competitor, Ford's 6.7L Power Stroke V-8. In 2016, engine torque was yet again increased for the HO model, yielding a peak 900 lb-ft as a result of a revised engine calibration. The HO engine remains exclusive to Ram 3500 models and comes standard with the Aisin automatic transmission.

6.7l Cummins Tops 1,000 lb-ft For 2019 Model Year

The H.O. 6.7L Cummins turbodiesel received a 400 horsepower, 1,000 lb-ft rating for the 2019 model year, setting a record as the first manufacturer in the light duty segment to push an engine into quadruple digit torque. Engine enhancements included:

• Deep skirt compacted graphite iron (CGI) engine block manufactured by TUPY; significant strength improvement over previous cast iron engine block and reduced engine weight.
• Revised piston design with low friction piston rings, enlarged wrist pin diameter. Compression ratio decreased to 16.2 : 1 for high output engines, increased to 19.0 : 1 for standard output engines.
• Forged steel connecting rods (previous engines featured powdered metal rods).
• Maintenance free, self-adjusting hydraulic lifters replace previous solid lifter/camshaft arrangement.
• Revised rocker arm and exhaust valve system.
• Cylinder head bolt diameter increased.
• Bosch CP4.2 high pressure injection pump replaces CP3 used in previous years. Max injection pressure increased from 26,000 to 29,000 psi (CP4.2 injection pump rumored to have a much higher pressure capability than being utilized by 6.7L Cummins, likely for improved reliability).
• Revised fuel injector design.
• Moderate design changes to Holset variable geometry turbocharger; new turbocharger model has yet to be confirmed. Engine operates at maximum 33 psi of manifold pressure.
• Revised exhaust manifold; turbocharger now positioned between cylinder 4 and 5 runners (previously located centrally between cylinder 3 and 4 runners).
• Increased cooling system capacity.
• High volume oil pump.
• Water and oil pumps now reside in aluminum housings (previously cast iron).

The engine helps celebrate the 30th anniversary of the relationship between Cummins and Ram Trucks (formerly Dodge). Cummins first supplied its 6BT for the 1989 model year Dodge 3/4 and 1 ton pickups. 2019 represents the 12th year of production for the 6.7L Cummins turbodiesel, which has undergone a series of improvements and revisions since its inception near the middle of the 2007 model year.

6.7L Cummins Horsepower & Torque Charts

2010 (left) and 2011 (right) hp/torque charts shown below.

2010 6.7 Cummins torque curve2011 6.7 Cummins torque curve

Source: Cummins Inc.