If you own a 2013-2018 Ram 2500, 3500, 4500, or 5500 with the 6.7L Cummins diesel, your fuel system uses a two-filter design — unlike the newer 2019+ trucks, which added a dedicated fuel/water separator. Understanding why both filters matter helps explain why skipping one during a service can leave your engine only half-protected.
1. Two Filters, Two Jobs
The 68157291AA filter handles primary fuel filtration, while the 68197867AB filter provides secondary filtration further down the fuel line. Together they trap contaminants and moisture before fuel reaches the high-pressure common rail injectors — replacing only one leaves a gap in protection.
2. Signs It's Time to Replace
Watch for reduced power under load, rough idle, longer cranking times before startup, or a noticeable drop in fuel economy. On the 6.7L Cummins, these symptoms often show up gradually, making it easy to miss until performance has already dropped.
3. Recommended Interval
Mopar recommends replacing both fuel filters and the oil filter every 15,000 miles for fuel filters, and at every oil change (7,500-10,000 miles) for the oil filter — sooner if you tow frequently or drive in dusty conditions.
4. Why Genuine Mopar Matters Here
Because this fuel system relies on precise filtration at high injection pressure, using OEM-spec Mopar filters — not lower-quality aftermarket substitutes — protects the injectors from the kind of damage that costs far more to repair than the filter kit itself.
5. A Simple DIY Job
Changing all three filters (both fuel filters plus the oil filter) is a routine job most Ram owners can handle in under an hour with basic hand tools.
👉 Shop the Genuine Mopar 6.7L Cummins Fuel & Oil Filter Kit (2013-2018) — free worldwide shipping, and a free step-by-step install video included with every order.