6.7L Cummins Horsepower and Torque, by Configuration

6.7L Cummins Horsepower and Torque, by Configuration T1a · The Diesel Dudes 6.7L Cummins Horsepower and Torque, by Configuration By The Diesel Dudes technical team On this page The current published figures Why one engine has several numbers The 2021 figures do not agree across the two manufacturers The chassis-cab figures are a separate set Where the engine started The 6.7L's own launch numbers How the figures have moved since What is behind the numbers Weight, and why the published figure moves Durability, which is the number that outlives the others The gas engine in the same trucks is a different conversation Reading a spec sheet correctly Sources Element 3 (Key Takeaways) — WAIVED: no key_takeaways in metadata (author in 2b). Not fabricated. Element 4 (Introduction) — WAIVED: no intro in metadata (author in 2b). Not fabricated.

The current published figures

On Cummins' latest-generation page for the engine, the headline pickup rating is stated simply. Power 430 hp [1] The matching torque figure on that same page is stated in the same form. Torque 1075 lb-ft [1] Cummins describes the engine there in general terms rather than by model year: The latest generation Cummins 6.7L Turbo Diesel is a heavy-duty pickup engine that delivers the power, towing performance, quietness, cold-weather reliability, and serviceability that truck owners depend on every day. [1] That page also lists a second, lower pickup rating. Power 360 hp [1] Its torque figure is stated as Torque 800 lb-ft, and there is a third band on the same page, wider than either of the first two. [1] Power 325 - 385 hp [1] Its torque range is given as Torque 610 - 930 lb-ft. [1] Three sets of numbers, one engine family, one page — which is exactly where the confusion starts for most owners.

Why one engine has several numbers

The ratings are not marketing variants. They track real differences in what the drivetrain behind the engine can absorb, and Cummins is explicit about the pairing. Take the 2021 model year, where the split is documented plainly. The high-output figures are the ones most often quoted: The new high-output engine boasts 420 hp and 1,075 lb-ft of best-in-class torque. [2] But that rating is not available across the range. This high-output (HO) rating is offered exclusively in the RAM 3500 equipped with the Aisin transmission option. [2] One chassis, one transmission. A 2500 cannot be ordered with it. The volume configuration for that year carries a different pair: For RAM 2500 and 3500 (equipped with a 68RFE Auto) HP and torque have increased to 370 hp and 850 lb-ft to provide the right power for these models. [2] Note Cummins' own phrasing — "the right power for these models." The lower rating is a deliberate match to the driveline, not a detuned version of the better one. That is why the model-year page for 2021 states its outputs as ranges rather than single values. Power 370 - 420 hp [2] The corresponding torque span is stated the same way. Torque 850 - 1075 lb-ft [2] Read as a range covering configurations, those numbers are unambiguous. Read as a single claim about a single truck, they are unusable — and that is the mistake most spec arguments are built on. Cummins also notes what the top figure meant for buyers at the time: HD pickup buyers can get an impressive 1,075 lb-ft of torque. [2]

The 2021 figures do not agree across the two manufacturers

Here is the specific reason you will find two different high-output numbers for the same truck, and it is not that one of the sources is a rumour. Both are manufacturer material. Cummins publishes the model year in its own page title: Engines | Cummins 6.7L Turbo Diesel (2021) | Cummins Inc. [2] That page gives the high-output rating as 420 hp and 1,075 lb-ft. Ram's own press material for the same model year states it differently. The document identifies its year in its opening line: The 2021 Ram Heavy Duty offers a towing capacity of 35,100 pounds and a payload capacity of 7,680 pounds. [3] And it gives the high-output engine a lower pair of numbers: 6.7-liter Cummins High-Output Turbo Diesel: produces 400 horsepower and 1,000 lb.-ft. of torque (Ram 3500) [3] The two documents do agree on the volume rating. 6.7-liter Cummins Standard-Output Turbo Diesel: produces 370 horsepower and 850 lb.-ft. of torque (Ram 2500 and 3500) [3] So the disagreement is confined to the high-output figure: 420 hp and 1,075 lb-ft on the engine maker's page, 400 horsepower and 1,000 lb-ft in the truck maker's release. The safe habit is to take engine ratings from the engine maker and stay with one set, because mixing the two inside a single comparison is how a spec argument becomes unwinnable. The documents themselves show one more thing worth noticing. Later Ram press material does carry the higher pair: 6.7-liter Cummins High-Output Turbo Diesel produces 420 horsepower and 1,075 lb.-ft. of torque (Ram 3500) [4] And that later document describes a different truck around the same engine: The most powerful, most capable pickup in the segment offers a towing capacity of up to 37,090 pounds and a payload capacity of 7,680 pounds. [4] It also dates itself by a feature note: New digital rearview mirror with side camera integration is an available option for 2023. [4] The higher output, in other words, appears in the material describing the higher towing rating. If you are checking a specific truck, the transmission and the model year on the door jamb settle it — not a number quoted from a document about a different year.

The chassis-cab figures are a separate set

Chassis cab trucks are rated separately again, and they are the reason the lower bands on the current page exist. For the 2019 model year: In 2019, RAM 3500, 4500 and 5500 Chassis Cab models equipped with a Aisin automatic, see an increase in horsepower and torque to 360 hp and 800 lb-ft. [5] So a 360 hp figure is not a "weaker" 6.7L in any meaningful sense. It is the chassis-cab calibration, in a truck built for a different job, behind a different transmission. Anyone comparing a chassis cab against a 3500 pickup on horsepower alone is comparing two different products.

Where the engine started

The output history explains why so many overlapping numbers exist, and it starts before the 6.7L. Cummins dates the partnership itself: In 2019, we celebrated a 30-year partnership with RAM truck that started with the Cummins 5.9L Turbo Diesel in model year 1989. [2] The first engine's numbers are a useful anchor for how far the ratings have travelled. From our 5.9-liter, 160-horsepower beginnings to the 6.7-liter, 400-horsepower engines available in today’s RAM pickups, Cummins and RAM lead the way in innovation, power and durability. [6] The torque figure on that first truck was the headline at the time: With 400 pounds-feet of torque, it roared past the competition. [6] Four hundred pound-feet was a segment-beating number in 1989. It is now below the torque rating of the lowest band on the current page.

The 6.7L's own launch numbers

The 6.7L arrived for the 2007 model year, replacing the 5.9L, and its launch figures came with engine speeds attached — which is more information than most current spec sheets give you. Producing 350 horsepower at 3,000 rpm and 650 lb.-ft. of torque at 1,500 rpm, the 6.7-liter engine features an all-new six-speed automatic transmission that delivers improved fuel economy and performance. [7] Torque at 1,500 rpm is the part worth noticing. Peak torque low in the rev range is what makes a diesel useful for towing, and it is why comparing a diesel's horsepower against a petrol engine's tells you very little. The engine was physically bigger than the one it replaced, and the press material gives the dimensions: the new 6.7-liter engine is 50-percent quieter, while featuring a 107mm bore by 124mm stroke (versus 102mm bore by 120mm stroke for the 5.9-liter engine) [7] Its displacement in the units American buyers still use: The high-performance 408-cubic-inch inline-six intercooled turbo-diesel is clean and quiet, and meets all 2007 U.S. federal and state emission requirements, which require a 90-percent reduction in particulate matter and 50-percent reduction in NOx. [7] The mechanism behind the launch numbers was the turbocharger, and its design is described in detail: The 6.7-liter engine’s VGT utilizes 16 fixed vanes and a sliding yoke, providing variable geometry, as well as an electric valve. [7] A variable-geometry turbocharger is what lets one turbo suit both low-rpm torque and high-rpm airflow, which is the engineering reason a single-turbo engine could carry both those figures at once. That launch also brought a feature that changes how the engine is used rather than what it produces: an integrated exhaust brake is available direct from the factory [7]

How the figures have moved since

Two later markers are worth knowing. The first is the torque milestone. The 2019 model year introduced HD pickup buyers to 1000 lb-ft of torque for the first time ever. [8] The most recent step is already announced. The new 2025 Cummins 6.7-liter Turbo Diesel advanced engine system and powertrain will be offered in the recently announced 2025 Ram 2500, 3500 Heavy Duty pickups and Ram 3500, 4500 and 5500 Chassis Cab trucks. [8] Pickups and chassis cabs together, which is why the current page carries pickup and chassis-cab bands side by side. For context on how common the engine is in these trucks: Nearly 70% of all Ram 2500 and 3500 Heavy Duty pickup owners choose the Cummins Turbo Diesel as their powertrain of choice. [8]

What is behind the numbers

Two engineering changes explain how the higher ratings became possible, and both are more informative than the output figures alone. The block material changed. A Compacted Graphite Iron (CGI) material for the block allows us to increase the cylinder pressure capability while reducing the overall weight by almost 60 lbs [5] Higher cylinder pressure is what higher torque requires, and CGI let Cummins raise the ceiling while taking mass out rather than adding it. The fuel system changed with it. The new fuel-delivery system includes a new 29,000 psi (2,000 bar) fuel pump and fuel rail with Cummins Filtration “filter in filter” NanoNet® technology [5] Injection pressure of that order is what makes the combustion work at those cylinder pressures.

Weight, and why the published figure moves

Anyone weighing the engine into a build will find two different masses published, and the difference is the application rather than an error. The 2021 pickup engine page gives it as Engine Wet Weight 1,070 lbs. [2] The 2019 chassis-cab page for the same engine family gives a different figure: Engine Wet Weight 1026 lb (465 kg) [5] So "how much does a 6.7 Cummins weigh" has the same shape of answer as "how much power does it make." Name the year and the application, or the number does not mean anything.

Durability, which is the number that outlives the others

Output figures date quickly. The service-life figure Cummins and Dodge published at launch has aged better: Life-to-major overhaul intervals of 350,000 miles, providing more than a 100,000-mile advantage over the competition [7] The emissions hardware carried its own certified life from the start: The emissions system is designed for a government-certified 120,000 miles. [7] Those two numbers are the reason a high-mileage 6.7L is a normal used truck rather than a gamble, and they are also the reason the engine's output ratings matter less than owners assume. A 350 hp 2007 truck and a 430 hp current one are the same basic architecture with 350,000-mile overhaul intervals behind both.

The gas engine in the same trucks is a different conversation

Because these trucks are also sold with a petrol engine, its figures turn up in the same searches and get mistaken for diesel numbers. 6.4-liter HEMI V-8: delivers best-in-class gas engine power – 410 horsepower at 5,600 rpm and 429 lb.-ft. of torque at 4,000 rpm [3] Look at where those peaks sit. Four hundred and ten horsepower at 5,600 rpm and 429 lb-ft at 4,000 rpm is a completely different character from 850 lb-ft down at low revs. A gas engine with more headline horsepower than the standard-output diesel still has less than half its torque.

Reading a spec sheet correctly

Four habits will keep you out of the common errors. Match the figure to a configuration, never to the engine. "The 6.7 Cummins makes 1,075 lb-ft" is not true of the engine. It is true of the high-output rating in a RAM 3500 with the Aisin transmission. The same sentence about a 2500 is wrong. Check the transmission before the horsepower. The 68RFE and Aisin configurations carry different ratings in the same model year. On a used truck, the transmission is the fastest way to work out which rating you are actually looking at. Treat ranges as ranges. When a manufacturer page states power as a span, it is describing a family of configurations, not a tolerance band on one engine. Separate pickups from chassis cabs. They are rated apart, for different duty cycles, and mixing them is the single most common source of contradictory numbers online. Cummins summarises the direction of travel for the 2021 engine in one line, and it is a fair description of the whole run: The 2021 6.7L Cummins Turbo Diesel brings to the table even more horsepower and torque while maintaining the diesel’s historic durability and efficiency. [2]

Sources

1. Cummins Inc., 6.7L Turbo Diesel — latest-generation engine page for Ram 2500 and 3500 2. Cummins Inc., Cummins 6.7L Turbo Diesel (2021) engine page 3. Cummins Inc., 6.7L Cummins Turbo Diesel (2019) for Chassis Cab 4. Cummins Inc., Cummins and Ram history 5. Cummins Inc., pickup truck engines overview, including the 2025 announcement 6. Ram Heavy Duty press material, 2021 model year — Stellantis North America media 7. Ram Heavy Duty press material, later model year — Stellantis North America media 8. Dodge Ram Heavy Duty 6.7-liter launch release, 2007 model year — Stellantis North America media Element 20 (Vehicle compatibility table) — WAIVED: no product on this article carries a fitment record in the catalogue. Not fabricated. Element 22 (Technical specs table) — WAIVED: no product on this article carries variant records in the catalogue. Not fabricated. Element 8 (Expert quote) — WAIVED: no claim on this article is declared as a quote, and the profile's technical-sources pool is a domain allowlist that carries no quotations, so no sourceable attributed quote exists. Not fabricated. Element 16 (The Bottom Line) — WAIVED: no bottom_line in metadata (author in 2b). Not fabricated. Element 9 (FAQ) — WAIVED: no faq in metadata (author in 2b). Not fabricated.

Sources & References

Cummins Inc. — 67l engine ram 2500 and 3500 — https://www.cummins.com/engines/pickup-truck/67l-engine-ram-2500-and-3500 Cummins Inc. — Cummins 67l turbo diesel 2021 — https://www.cummins.com/engines/products/cummins-67l-turbo-diesel-2021 Stellantis North America (Ram Trucks / Dodge) media newsroom — Newsrelease.do — https://media.stellantisnorthamerica.com/newsrelease.do?id=21972 Stellantis North America (Ram Trucks / Dodge) media newsroom — Newsrelease.do — https://media.stellantisnorthamerica.com/newsrelease.do?id=24053&mid=71 Cummins Inc. — 67l cummins turbo diesel 2019 chassis cab — https://www.cummins.com/engines/products/67l-cummins-turbo-diesel-2019-chassis-cab Cummins Inc. — Cummins ram history — https://www.cummins.com/engines/pickup-truck/cummins-ram-history Stellantis North America (Ram Trucks / Dodge) media newsroom — Newsrelease.do — https://media.stellantisnorthamerica.com/newsrelease.do?id=6229&mid=97 Cummins Inc. — Pickup truck — https://www.cummins.com/engines/pickup-truck Element 24 (Internal link block) — WAIVED: no internal_links in metadata (author in 2b). Not fabricated.

About this article

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