6.7 Cummins: years, specs & known problems

By CarWhere Research · Updated November 3, 2026

The 6.7 Cummins is the 6.7-liter inline-six turbo diesel in Ram 2500 and 3500 pickups since mid-2007. It launched at 350 hp and 650 lb-ft, reached 420 hp and 1,075 lb-ft in High Output form for 2021, and for 2025 makes 430 hp and 1,075 lb-ft as the only Cummins rating in Ram pickups.

The 6.7 replaced the 5.9 during the 2007 model year, growing to 408 cubic inches with a 4.21 × 4.88-inch bore and stroke, a variable-geometry Holset turbo, an EGR cooler and a diesel particulate filter. Diesel exhaust fluid (SCR) arrived for 2013, along with the Aisin six-speed High Output version for the Ram 3500. For 2019 Cummins switched to a compacted graphite iron block and a CP4.2 high-pressure pump; for 2021 the High Output rating rose to 420 hp and 1,075 lb-ft and the CP3 pump returned.

The 2025 Ram 2500 and 3500 pickups got a revised 6.7 rated at 430 hp and 1,075 lb-ft with a new fuel pump, top-feed injectors, a new variable-geometry turbo and an eight-speed automatic, while chassis cabs are rated at 360 hp and 800 lb-ft. The biggest documented issue is the 2019–2020 CP4.2 fuel pump, covered by recall 21V880, which replaces it with a CP3.

6.7 Cummins at a glance

Cummins 6.7L turbo diesel I6 (Ram heavy duty, 2007.5–present): model years, fuel and peak Stellantis-published output by version
Engine	Model years	Fuel	Peak hp	Peak torque (lb-ft)	Documented problems	Recalls
2007.5–2012 6.7 Cummins (DPF, no DEF)	2007.5–2012	Diesel	350	800	0	2
2013–2018 6.7 Cummins (DEF/SCR, Aisin High Output)	2013–2018	Diesel	385	930	1	2
2019–2024 6.7 Cummins (CGI block, Standard and High Output)	2019–2024	Diesel	420	1,075	1	4
2025–present 6.7 Cummins (430 hp, eight-speed)	2025–present	Diesel	430	1,075	0	0

CarWhere lists 2 documented problems and 8 NHTSA recalls for the 6.7 Cummins, each with a source.

2007.5–2012 6.7 Cummins (DPF, no DEF)

First 6.7 Cummins, with a variable-geometry turbo, EGR cooler and diesel particulate filter but no DEF system.

2007.5–2012 6.7 Cummins (DPF, no DEF) specifications

2007.5–2012 6.7 Cummins (DPF, no DEF): design facts (2007.5–2012)
Specification	Value
Displacement	6.7 L (408 cu in)[1]
Bore × stroke	4.21 in × 4.88 in[1]
Fuel system	High-pressure common rail, Bosch CP3 pump[1]
Turbo	Holset variable-geometry (VGT)[1]
Emissions	EGR cooler, diesel particulate filter, catalytic converter[1]
Peak injection pressure	About 26,000 psi (vs 23,200 psi on the 5.9)[2]

2007.5–2012 6.7 Cummins (DPF, no DEF) horsepower and torque by year

2007.5–2012 6.7 Cummins (DPF, no DEF): Stellantis-published horsepower (hp) and torque (lb-ft) by model year and application
Model years	Application	Horsepower (hp)	Torque (lb-ft)	Source
2007.5–2010	Automatic (68RFE)	350	650	[1]
2007.5–2012	Manual (G56)	350	610	[1]
2011–2012	Automatic (68RFE)Some references date the 800 lb-ft rating to February 2011 production	350	800	[1]

"—" means we could not confirm the figure from a primary source.

Which vehicles have the 2007.5–2012 6.7 Cummins (DPF, no DEF)?

Models and model years offered with the 2007.5–2012 6.7 Cummins (DPF, no DEF)
Model	Model years	Notes
Dodge Ram / Ram 2500 and 3500 pickups	2007.5–2012

2007.5–2012 6.7 Cummins (DPF, no DEF) recalls

NHTSA safety recalls related to the 2007.5–2012 6.7 Cummins (DPF, no DEF) (campaign numbers link to NHTSA)
NHTSA campaign	Reported	Vehicles	Summary
08V641	2008-12	2007–2008 Dodge Ram 2500/3500 with the 6.7L diesel108,429 vehicles	A silencer pad can sag onto the EGR cooler, creating an engine compartment fire risk. Dealers add a support bracket.
14V635	2014-10	2010–2014 Ram 2500, 3500, 4500 and 5500 diesel trucks built March 2009–September 2013	Diesel fuel heater connectors can overheat and the heater can leak fuel, raising fire risk. Dealers replace the connector terminals and inspect the heater.

2013–2018 6.7 Cummins (DEF/SCR, Aisin High Output)

Adds diesel exhaust fluid (SCR) and three ratings by transmission: G56 manual, 68RFE automatic and, in the Ram 3500, the Aisin AS69RC High Output.

2013–2018 6.7 Cummins (DEF/SCR, Aisin High Output) specifications

2013–2018 6.7 Cummins (DEF/SCR, Aisin High Output): design facts (2013–2018)
Specification	Value
Valvetrain	OHV, 24 valves, solid lifters[3]
Construction	Cast-iron block and head[3]
Compression ratio	16.5:1[3]
Emissions	Diesel exhaust fluid (SCR) from 2013[3]
Oil capacity	12.0 qt with filter[3]

2013–2018 6.7 Cummins (DEF/SCR, Aisin High Output) horsepower and torque by year

2013–2018 6.7 Cummins (DEF/SCR, Aisin High Output): Stellantis-published horsepower (hp) and torque (lb-ft) by model year and application
Model years	Application	Horsepower (hp)	Torque (lb-ft)	Source
2013–2018	Manual (G56)	350	660	[3]
2013–2018	Automatic (68RFE)	370	800	[3]
2013–2014	High Output, Aisin AS69RC (3500)	385	850	[3]
2015	High Output (3500)	385	865	[4]
2016–2017	High Output (3500)	385	900	[4]
2018	High Output (3500)	385	930	[4]

"—" means we could not confirm the figure from a primary source.

Which vehicles have the 2013–2018 6.7 Cummins (DEF/SCR, Aisin High Output)?

Models and model years offered with the 2013–2018 6.7 Cummins (DEF/SCR, Aisin High Output)
Model	Model years	Notes
Ram 2500 / 3500 pickups	2013–2018
Ram 3500 pickup, High Output with Aisin AS69RC	2013–2018

2013–2018 6.7 Cummins (DEF/SCR, Aisin High Output) problems and what to check

Head gasket failure on modified, high-drive-pressure trucks (2007.5–present (mainly tuned trucks))

Moderate

The 6.7's longer stroke raises cylinder pressure compared with the 5.9, and aggressive tuning can push turbo drive pressure well above boost. Head gasket failures are uncommon on stock engines, many of which pass 200,000 miles, but are a known risk on heavily modified trucks; head studs are the usual upgrade.[2]

Symptoms

Coolant loss with no external leak
White exhaust smoke
Pressurized coolant overflow after towing

Check before buying

Ask whether the truck has been tuned or had emissions parts removed
Run a cooling-system pressure or combustion-gas test
Check for head-stud receipts on modified trucks

2013–2018 6.7 Cummins (DEF/SCR, Aisin High Output) recalls

NHTSA safety recalls related to the 2013–2018 6.7 Cummins (DEF/SCR, Aisin High Output) (campaign numbers link to NHTSA)
NHTSA campaign	Reported	Vehicles	Summary
15V592	2015-09	2016 Ram 2500/3500 and 3500–5500 chassis cab with the 6.7L Cummins built July 31–Aug. 13, 2015	The engine control module may short-circuit and stall the engine without warning. Dealers replace the ECM.
17V562	2017-09	2013–2017 Ram 2500, 3500 and 3500–5500 chassis cab with the 6.7L Cummins and an unvented Concentric water pump	The water pump can leak coolant, increasing the risk of an engine compartment fire. Dealers replace the water pump.

2019–2024 6.7 Cummins (CGI block, Standard and High Output)

Redesigned 6.7 with a compacted graphite iron block, offered as a 370-hp standard output with the 68RFE and a High Output with the Aisin six-speed in the Ram 3500.

2019–2024 6.7 Cummins (CGI block, Standard and High Output) specifications

2019–2024 6.7 Cummins (CGI block, Standard and High Output): design facts (2019–2024)
Specification	Value
Block	Compacted graphite iron, cast-iron head; over 60 lb lighter than before[5]
Turbo	Variable-geometry, up to 33 psi boost[5]
High-pressure fuel pump	Bosch CP4.2 on 2019–2020; CP3 from 2021[7]
High Output transmission	Aisin AS69RC six-speed automatic[8]

2019–2024 6.7 Cummins (CGI block, Standard and High Output) horsepower and torque by year

2019–2024 6.7 Cummins (CGI block, Standard and High Output): Stellantis-published horsepower (hp) and torque (lb-ft) by model year and application
Model years	Application	Horsepower (hp)	Torque (lb-ft)	Source
2019–2020	Standard output850 lb-ft at 1,700 rpm	370	850	[5]
2019–2020	High Output (3500)1,000 lb-ft at 1,800 rpm	400	1,000	[5]
2021–2024	Standard output	370	850	[6]
2021–2024	High Output (3500, Aisin)	420	1,075	[6]

"—" means we could not confirm the figure from a primary source.

Which vehicles have the 2019–2024 6.7 Cummins (CGI block, Standard and High Output)?

Models and model years offered with the 2019–2024 6.7 Cummins (CGI block, Standard and High Output)
Model	Model years	Notes
Ram 2500 / 3500 pickups, standard output	2019–2024	68RFE six-speed automatic
Ram 3500 pickup, High Output	2019–2024	Aisin AS69RC six-speed automatic

2019–2024 6.7 Cummins (CGI block, Standard and High Output) problems and what to check

CP4.2 high-pressure fuel pump failure (2019–2020)

Major repair

The 2019–2020 6.7 used a Bosch CP4.2 pump. If air enters the fuel, the pump's roller tappets can rotate and wear against the cam, sending metal debris through the injectors, rails and return lines, and the engine can stall without warning. Recall 21V880 replaces the CP4.2 with a CP3 and reflashes the engine computer; Ram returned to the CP3 for 2021.[9][10][7]

Symptoms

Stall without warning
Hard start or no start
Fuel-pressure or rail-pressure fault codes

Check before buying

Confirm recall 21V880 was completed (CP3 pump installed)
Ask for fuel-filter service records and proper priming
Run an NHTSA VIN recall check

Stellantis program: NHTSA recall 21V880

Reported repair cost: $6,000–$10,000+ for an out-of-warranty fuel-system contamination repair[7]

2019–2024 6.7 Cummins (CGI block, Standard and High Output) recalls

NHTSA safety recalls related to the 2019–2024 6.7 Cummins (CGI block, Standard and High Output) (campaign numbers link to NHTSA)
NHTSA campaign	Reported	Vehicles	Summary
19V498	2019-06	2019 Ram 2500/3500 and 3500–5500 chassis cab with the diesel engine	Fuel lines may leak diesel into the engine compartment, a fire risk. Dealers inspect and replace the lines.
21V880	2021-11	2019–2020 Ram 2500/3500 and 3500–5500 chassis cab with the 6.7L Cummins	The high-pressure fuel pump can fail and stall the engine without warning. Dealers replace the CP4.2 pump with a CP3, reflash the engine computer and replace contaminated parts as needed.
22V642	2022-08	2022 Ram 2500/3500 and 3500–5500 chassis cab with the 6.7L Cummins	A misaligned capacitor in the engine control module can short, causing a communication loss and possible loss of drive power.
23V060	2023-02	2021–2023 Ram 2500/3500 and 3500–5500 chassis cab with the 6.7L Cummins	The intake heater grid relay can short and cause an engine compartment fire with the ignition on or off. Expands and supersedes 21V163 and 21V798.

2025–present 6.7 Cummins (430 hp, eight-speed)

Revised 6.7 with a new high-pressure fuel system, top-feed injectors and a new variable-geometry turbo, offered in Ram pickups in one High Output rating with a new eight-speed automatic.

2025–present 6.7 Cummins (430 hp, eight-speed) specifications

2025–present 6.7 Cummins (430 hp, eight-speed): design facts (2025–present)
Specification	Value
Fuel system	New high-pressure pump with top-feed, dry-service injectors[11]
Turbo	New variable-geometry turbocharger[11]
Transmission	New TorqueFlite HD eight-speed automatic[12]
Serviceability	Top-mounted oil filter and dual fuel filters; in-truck software updates[11]
Built in	Columbus, Indiana[11]

2025–present 6.7 Cummins (430 hp, eight-speed) horsepower and torque by year

2025–present 6.7 Cummins (430 hp, eight-speed): Stellantis-published horsepower (hp) and torque (lb-ft) by model year and application
Model years	Application	Horsepower (hp)	Torque (lb-ft)	Source
2025–present	Ram 2500/3500 pickup	430	1,075	[11]
2025–present	Ram 3500–5500 chassis cab	360	800	[11]

"—" means we could not confirm the figure from a primary source.

Which vehicles have the 2025–present 6.7 Cummins (430 hp, eight-speed)?

Models and model years offered with the 2025–present 6.7 Cummins (430 hp, eight-speed)
Model	Model years	Notes
Ram 2500 / 3500 pickups	2025–present	High Output rating only
Ram 3500, 4500, 5500 chassis cab	2025–present

6.7 Cummins issues by model

The same engine shows up on these known-issues pages, with model-specific details.

Ram 2500 and 3500: 6.7 Cummins water pump leak (recall 17V562) (2013–2017)
Ram 2500 and 3500: 6.7 Cummins CP4 high-pressure fuel pump failure (recall 21V880) (2019–2020)
Ram 2500 and 3500: Intake grid heater relay short can cause a fire (recalls 21V163, 21V798, 23V060) (2021–2023)

Related Ram, Jeep and Dodge research

Confirm a vehicle really has the 6.7 Cummins.

The engine a Ram left the factory with is part of its build record. The CarWhere Ram build sheet reconstructs factory colors, options and packages from licensed VIN-level build data — availability is checked free, and it is $9.99 only when detailed build data is found for that VIN.

Ram build sheet by VIN

Frequently asked questions

What years did the 6.7 Cummins have the CP4 pump?

2019 and 2020. Recall 21V880 replaces the CP4.2 with a CP3, and Ram went back to the CP3 for 2021 production.

How much horsepower does the 6.7 Cummins have?

350 hp at launch in 2007.5, 370–385 hp for 2013–2018, 370 hp standard or 400–420 hp High Output for 2019–2024, and 430 hp with 1,075 lb-ft in 2025 and later Ram pickups.

When did the 6.7 Cummins get DEF?

Ram pickups added diesel exhaust fluid (SCR) for the 2013 model year. The 2007.5–2012 trucks have a diesel particulate filter and EGR but no DEF.

What is the High Output 6.7 Cummins?

From 2013 to 2024 it was the stronger rating sold in the Ram 3500 with the Aisin six-speed, peaking at 420 hp and 1,075 lb-ft. For 2025 the 430-hp High Output is the only Cummins rating in Ram 2500 and 3500 pickups.

Which 6.7 Cummins years have the most recalls?

The 2019–2024 trucks carry the most engine-related recalls, including 21V880 (fuel pump), 22V642 (engine control module) and 23V060 (grid heater relay). Run the VIN on NHTSA to confirm completion.

Sources

Ratings are Stellantis-published figures as cited; descriptions are CarWhere’s own summaries of the sources below. Repair costs appear only where a source states them and vary by shop and region.

Cummins Diesel: The Engine That Powers The Ram (May 2015) — Diesel Army
Performance Roadblocks of the 6.7L Cummins (Apr. 2020) — Driving Line
2013 Ram 2500 & 3500 Heavy Duty Preliminary Specifications — Chrysler Group LLC media
5.9L, 6.7L Cummins Horsepower & Torque By Model Year — DieselHub (secondary reference)
New 2019 Ram Heavy Duty is the Benchmark for Performance, Capability, Technology and Luxury (Jan. 14, 2019) — FCA US LLC (via Automotive World)
2023 Ram 3500 4x4 engine performance and towing — Ram (ram.com)
Making The Cummins Great Again—With A Factory CP3 Fuel Pump Swap (Jan. 2022) — Driving Line
2019 Ram Heavy Duty Offers 1,000 ft.-lb. Torque Rating — For Construction Pros (FCA release)
Safety Recall 21V880: 2019–2020 Ram HD with 6.7L Cummins (high-pressure fuel pump) — National Highway Traffic Safety Administration (NHTSA)
The Recall You Wanted: Cummins CP4 (Aug. 2023) — Diesel World
Cummins Launches Next Generation 6.7L Turbo Diesel Pickup Engine System for 2025 Ram Heavy Duty Trucks (Jan. 7, 2025) — Cummins Inc. (Business Wire)
Ram unveils the new 2025 2500 and 3500 Heavy Duty — NTEA Work Truck Week (Ram release)

More Ram tools

Independent reference compiled by CarWhere — not affiliated with or endorsed by Stellantis or Cummins Inc. Ram, Jeep, Dodge, HEMI, SRT, Hellcat, Hurricane and the model names are trademarks of their owners.