Close-up of a 6.7L Cummins Turbo Diesel engine with a mechanic’s gloved hand holding a wrench during inspection.

6.7L Cummins Engine Updates by Year (2009–2025)

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Posted in Engine Platforms (Cummins, Duramax, Power Stroke)

The 6.7L Cummins Turbodiesel has been the backbone of Ram heavy-duty trucks for well over a decade. As competition between diesel manufacturers intensified, Cummins introduced a steady stream of upgrades—boosting power, refining emissions systems, and strengthening internal components to handle ever-increasing torque.

Below is the complete model-year breakdown from 2009 through 2025, including horsepower, torque, emissions changes, and major mechanical upgrades.

2009: Early Refinements

Cummins made several serviceability and durability improvements, including:

  • Turbocharger turbine-housing access port (allows VGT vane cleaning without removing turbo)
  • Updated fuel filter housing & element
  • Redesigned water pump inlet housing
  • Updated EGR coolant hoses & fittings

These changes mainly improved reliability and maintenance.

2010: Electronics + Fuel System Updates

  • Transition to single PCM controlling both engine and transmission (replacing dual-unit system)
  • Revised fuel filter housing with quarter-turn drain valve
  • Updated thermostat (200°F opening temp)

A small but important step toward streamlining electronics and emissions controls.

2011: Torque Increase & SCR for Chassis Cabs

  • +150 lb-ft torque for 68RFE automatic models
  • G56 manual trucks unchanged
  • Chassis cab models received SCR/DEF systems for emissions compliance

This marked Cummins’ first major integration of DEF technology.

2013: Major Power Bump + High Output Debut

This was one of the most significant upgrade years in the engine’s history.

Power Increases

  • G56 chassis cab: +15 hp / +40 lb-ft
  • Automatic chassis cab: +20 hp / +140 lb-ft
  • Pickup G56: +50 lb-ft
  • Standard output: +20 hp (still 800 lb-ft)
  • High Output (H.O.) version introduced for Ram 3500
    • +15 hp, +50 lb-ft over standard

Mechanical Upgrades

  • New camshaft (chassis cab)
  • Redesigned pistons w/ skirt coating
  • New piston cooling jets
  • Updated vibration damper
  • Strengthened bedplate
  • Holset HE300VG turbo
  • Larger EGR cooler
  • Smaller water pump / fan pulley
  • New high-speed ECU
  • AS69RC transmission replaced AS68RC in chassis cabs

Emissions

  • SCR/DEF became standard on all pickup models

For official emissions standards related to diesel SCR and DEF systems, see the EPA’s engine and vehicle emissions resource.

https://www.epa.gov/vehicle-and-engine-emissions

2016: More Torque for H.O.

  • H.O. engines recalibrated to 900 lb-ft
  • Standard output unchanged

A small but meaningful bump, keeping Ram competitive.

2018: Torque Increase for H.O.

  • H.O. torque increased to 930 lb-ft
  • Standard output unchanged
  • Final year of the G56 manual transmission

2019: The Landmark Redesign

This year delivered the first-ever 1,000 lb-ft factory diesel pickup, and one of the most substantial mechanical overhauls Cummins has ever made.

Power Increases

  • H.O. torque: 930 → 1,000 lb-ft
  • Standard: 800 → 850 lb-ft
  • H.O. hp: 385 → 400 hp

Major Mechanical Redesigns

  • Compacted graphite iron (CGI) block (stronger & lighter)
  • Stronger pistons (new wrist pins, bowl geometry, low-friction rings)
  • Stronger forged rods & crankshaft
  • Updated cylinder head (new valves, springs, rocker arms, bolts)
  • Hollow camshaft + new lifters
  • Revised rocker arms
  • Updated Holset turbo (up to 33 psi boost)
  • New exhaust manifold + turbo relocation
  • Fuel system overhaul: Bosch CP4.2 pump and 29,000-psi injection
  • Revised injectors
  • Updated cooling and lubrication systems
  • Lighter aluminum oil and water pump housings

Note:

The CP4 pump caused reliability issues and was recalled/replaced in later years.

2020: Chassis Cab Only Power Increase

  • Chassis cab: +35 hp and +50 lb-ft
  • Pickup engines unchanged

2021: CP3 Returns + Slight H.O. Increase

  • Cummins returned to the Bosch CP3 pump (after CP4 failures)
  • Recall retrofit for 2019–2020 models
  • H.O. calibration: +20 hp and +75 lb-ft
  • Standard/chassis cab unchanged

2025: Major Lineup Simplification + Component Overhaul

For 2025, Ram moved to one diesel option: the H.O. 6.7L Cummins paired with the ZF PowerLine 8-speed automatic.

Mechanical & Systems Updates

  • New Bosch CP8 fuel pump (32,000 psi)
  • Traditional glow plugs (replacing grid heater)
  • New cartridge-style oil filter
  • Revised turbocharger
  • Engine-mounted DOC for faster light-off
  • Updated EGR system
  • All-new cylinder head with externally mounted injectors
  • Redesigned intake manifold for better airflow
  • Return to gray cast iron block (no longer CGI)
  • New piston design with lower 16.0:1 compression
  • ZF PowerLine 8-speed standard across all models
  • Pickup receives +10 hp over chassis cab

2025 represents the most refined, efficient, and service-friendly version of the 6.7L Cummins to date.

⭐ CONCLUSION

Across more than 15 years, the 6.7L Cummins has evolved significantly—gaining power, improving emissions compliance, strengthening internal components, and becoming more reliable overall. From the early VGT and EGR updates all the way to the high-compression 2025 redesign, the Cummins platform remains one of the most capable and trusted diesel engines ever produced.

If you’re researching diesel platform changes, you may also find our DEF System Deep Dive helpful, especially for understanding emissions-related updates.

https://www.northtexastruckstop.com/blog/def-system-how-it-works-symptoms-of-failure

FAQ

What year did the 6.7L Cummins reach 1,000 lb-ft of torque?

The 2019 model year marked the first time a factory pickup diesel reached 1,000 lb-ft, with the High Output 6.7L Cummins producing 400 hp and 1,000 lb-ft.

Which 6.7L Cummins years had major mechanical redesigns?

Significant redesigns occurred in 2013, 2019, and 2025, including turbo upgrades, block changes, new pistons, improved EGR components, and higher injection pressures.

Did the 6.7L Cummins switch back to the CP3 pump?

Yes. After reliability issues with the CP4.2 pump in 2019–2020 models, Ram recalled those trucks and returned to the CP3 pump starting in 2021.

What is the main difference between standard and High Output Cummins engines?

H.O. models typically feature higher torque, stronger internal components, larger turbos, and upgraded transmissions like the Aisin or ZF PowerLine.