PACCAR Aftertreatment (MX engine)
PACCAR · Aftertreatment / Emissions · DPF + SCR + DEF
What this component does
PACCAR Aftertreatment is the emissions control system for PACCAR MX-11 and MX-13 engines — used in Kenworth and Peterbilt trucks with PACCAR power. Similar architecture to Cummins and Detroit (DPF + DEF + SCR) but with PACCAR-specific calibration and parts. PACCAR-engined trucks have a separate aftertreatment supply chain from Cummins-engined trucks of the same OEM (e.g., a Kenworth T680 with PACCAR MX-13 has different aftertreatment parts than a T680 with Cummins X15).
Specifications
- Manufacturer
- PACCAR
- Category
- Aftertreatment / Emissions
- Subtype
- DPF + SCR + DEF
- Truck class
- Class 8
- Production
- 2010–present
- Applications
- All PACCAR MX-11/MX-13 engines (Kenworth + Peterbilt)
Design and engineering
PACCAR-integrated DOC + DPF + SCR + DEF dosing. Mounted in chassis like Cummins/Detroit. DEF tank 8-15 gallons.
Generations
- PACCAR Aftertreatment Original (2010–2018)First-generation SCR + DEF.
- PACCAR Aftertreatment Refined (2019–present)Refined SCR algorithms.
Reliability and longevity
Mixed history — PACCAR aftertreatment had more reliability issues than Cummins or Detroit in the EPA 2010-2014 era. Post-2017 improvements have closed the gap.
Common problems
DEF heater failures (industry-wide). EGR cooler cracking (more common on PACCAR MX-13 than Cummins X15). DPF plugging.
Maintenance schedule
DEF top-off, DPF cleaning, NOx sensor replacement at standard intervals.
Pros and cons
Pros
- ✓PACCAR-integrated with MX engine + TX-12 transmission
- ✓Kenworth/Peterbilt dealer service
- ✓Reliability improving 2017+
Cons
- !EGR cooler issues more common than Cummins/Detroit
- !Pre-2017 aftertreatment had higher failure rates
- !PACCAR-specific parts (less aftermarket choice)