The Unstoppable Cummins 6.7L Turbo Diesel

Ram 6.7L Cummins Turbo Diesel

Everything You Need to Know About the 2007.5–Present Cummins 6.7L

The Cummins 6.7L replaced the 5.9 mid-2007 and has powered Ram HD trucks ever since. With high-pressure common-rail fueling, a VGT turbo, and relentless low-rpm torque, it’s the go-to platform for work and play. Owners love the million-mile reputation—and with the right upgrades from BD Diesel, your 6.7L stays cool, responsive, and reliable under tow.

Specs & Attributes of the 6.7L Cummins

The 6.7L introduced EGR/DPF (later DEF/SCR), variable-geometry turbocharging (Holset family), and stout bottom-end architecture. Output varies by year/trans—newer HO trims crack four-figure torque.

• High-pressure common-rail injection
• VGT for fast spool and integrated exhaust brake
• Iron block, forged crank, heavy duty rods/pistons
• Paired with 68RFE, Aisin, and early G56 manual depending on trim/year

Common 6.7L Cummins Issues (What You’ll Notice First)

VGT Turbo Actuator or Sticking Vanes

Surging, lazy spool, inconsistent exhaust brake, or turbo speed codes. Heat/soot can stick vanes; electronics can fail.

EGR/DPF Driveability

Frequent regens, elevated EGTs, reduced performance—short trips and heavy idle accelerate soot loading.

Cooling/EGT Management Under Tow

Climbing coolant and trans temps on long grades—especially with oversized tires and tall gearing.

68RFE Converter Lockup Shudder

35–55 mph light-throttle “rumble strip,” shift flare, rising trans temps. Usually TCC glazing or unstable apply. See BD’s 68RFE Comprehensive Analysis.

Turbo Upgrades: Spool, EGT Control & Exhaust Brake Confidence

A healthy VGT is everything for response, EGTs, and braking. If your OE unit is sticking or the actuator is unreliable, upgrading restores control and protects the engine under tow. Explore BD’s engineered turbo solutions for 2013–2018 6.7L Cummins turbochargers to get back crisp spool and consistent exhaust-brake performance.

Exhaust Manifolds (2013–2018 & 2019–2024): Built for Heat Cycles

Thin tube headers crack; cast manifolds with uniform thickness survive. BD’s manifolds are designed for smoother port transitions that reduce drive pressure and help the turbo live longer. See our 6.7L Cummins exhaust manifolds for 2013–2018 and late-model 2019–2024.

68RFE Converter & Transmission: Stop Shudder at the Source

If you feel shudder during light-throttle lockup, fix it before the next tow. The BD 68RFE ProForce (Enhanced Stall) is sized for street/tow up to ~550 flywheel hp and keeps lockup stable on grades. If multiple clutch complaints or pressure faults show up, address the system in one shot with the Stock-Plus 68RFE Transmission + Converter Package.

Transmission Cooler Thermostat Bypass: Faster Flow, Lower Temps

The factory cooler thermostat can delay full flow, driving temps up right when you need cooling most. BD’s 68RFE Thermostat Bypass routes fluid to the cooler sooner for more consistent temperature control—especially helpful in hot climates, with bigger tires, or under heavy tow.

Most-Popular Upgrade: BD Killer Grid Heater

Cold-start reliability and electrical safety matter. The BD Killer Grid Heater re-engineers the weak points in the OE connection, maintains full heat output, and remains emissions compliant.

• Eliminates both problematic OE nuts by fastening directly into the lower busbar
• Allows full heat output with the stock intake grid heater
• Fully emissions compliant
• Easy installation; minor mod needed for 2007–2012 (see product notes)
• Includes replacement hardware, gaskets, and special tools
• Self-locking threads in the lower busbar prevent the connection backing out

Real work: stable EGTs and reliable lockup are everything.

Cummins 6.7L Specifications Chart

Towing Considerations

Ratings vary by cab/axle/dually and transmission. What doesn’t vary is the recipe for control: keep EGTs and trans temps in check, use the exhaust brake, and ensure stable torque-converter lockup. If you’re feeling shudder under light throttle, fix it before the next trip—start with the BD ProForce converter and consider the 68RFE Thermostat Bypass for faster cooler flow. For a deeper transmission breakdown, read BD’s Comprehensive Analysis.

Bring Your 6.7L to the Next Level

Teach it to work smarter, run cooler, and pull harder—with parts that solve problems, not create new ones. Shop BD direct or through trusted distributors: 6.7L Turbochargers (’13–’18) • Exhaust Manifolds (’13–’18 & ’19–’24) • 68RFE Thermostat Bypass • Killer Grid Heater • ProForce Converter • Stock-Plus 68RFE Package. Warranty info: BD Terms & Conditions.