By the numbers
At What Mileage Does a 6.7 Cummins Have Problems? What 63 Owners Said
Published · 2 min read
Low miles feel safe on a used diesel. For the 6.7 Cummins, the owners who told NHTSA when their truck failed say that is only half true: the emissions problems arrive early, the turbo actuator arrives in the middle.
In one minute
- DEF and DPF: a median of about 42,000 to 44,000 miles, and about half of them under 50,000.
- Turbo actuator: a median of 80,000 miles, mostly between 60,000 and 130,000.
- Grid heater bolt: only five owners gave a mileage, from 48,000 to 162,000.
- DEF / SCR systemmedian 41,614 miles (20 owners)
- DPF cloggingmedian 43,900 miles (19 owners)
- Turbo actuator / VGTmedian 80,000 miles (19 owners)
- Grid heater boltmedian 83,015 miles (5 owners)
NHTSA owner complaints filed on 2007-2018 Dodge and Ram 2500, 3500, 4500 and 5500 trucks, pulled 2026-09-12, extra NHTSA model names added 2026-10-10. Mileage read by hand from each complaint (article 018). Small samples: it shows when owners ran into a problem, not how long a part lasts.
What the dots say
The emissions side does not wait. DEF and DPF complaints start in the first few thousand miles (the lowest were 500 and 1,200) and run past 100,000. A truck that idled, towed short trips or never got hot enough to clean its filter can be in trouble at 30,000 miles. aggregated
The turbo actuator is a mid-life part. Its dots bunch in the middle of the scale: 11 of the 19 owners who gave a mileage were between 60,000 and 130,000. That is the window when a used truck changes hands. aggregated
The grid heater bolt shows up later, but with five owners we would not draw a line. It is the most expensive of the four when it goes wrong, which is why it gets its own quick read.
What to do with this
- On a truck under 50,000 miles, ask how it was driven and whether the DEF and DPF systems have codes or repairs. Low miles are not a clean bill of health.
- On a truck between 60,000 and 130,000, ask whether the turbo actuator was replaced. On a 2015 Ram 2500 or 3500, have a dealer check the VIN for the actuator extension (program X99). verified
- On a high-mileage truck, receipts beat the odometer: a replaced actuator and a fixed grid heater are worth more than 40,000 fewer miles.
The fine print: 63 owners, one number each, as they wrote it. This shows when owners ran into a problem, not how long a part lasts, and owners whose truck never failed do not write to NHTSA.
Want the whole picture? Era by era, recalls and what to check before you buy: Buying a used 6.7 Cummins (2007.5-2018).
Sources. NHTSA owner complaints database (US government public domain), mileage read by hand from each complaint in the set of our 6.7 Cummins articles. Ram program X99 (bulletin 09-005-22) from NHTSA's manufacturer communications index. Torque Index aggregates and cross-checks public information, takes no paid placement and does not provide repair or inspection services.