Cummins X15 / ISX15 / ISX Filters: Fuel, Oil, and Air

Fuel, oil, air, and water separator filtration for the Cummins flagship.

The same engine has had three names. Cummins called it ISX from 2002, ISX15 starting in 2010 with the EPA emissions update, and X15 from 2017 onward. Stage V arrived in 2020 with another set of filter spec changes. A fleet running trucks bought across that twenty-year span owns essentially one engine, but four to five different filter generations. Picking the wrong one for the wrong model year is the most common parts-counter mistake on this engine.

Steinberg stocks 9 filter SKUs that span the ISX, ISX15, and X15 lineage: three fuel filters (FF035 for X15 Stage V, FF036 for EPA 2010 ISX, FF012 for the secondary pressure-side position), three water separators (FF002 pre-EGR, FF004 Davco-housing 2013+, FF009 extended service), two lube filters (FO004 for X15/ISX15/ISX12, FO040 for ISM/ISX/QSX), and the FA001 air filter that fits the Kenworth, Peterbilt, and Volvo cabs housing most of these engines. Each is cross-referenced to Fleetguard FF, FS, and LF series part numbers and ships same-day from Hodgkins, IL. NET-30 terms for qualified fleet accounts.

For the Cummins ISB 6.7L medium-duty engine, see our Cummins ISB 6.7 / B6.7 Filters collection. For the broader Cummins catalog across all engine families, see our Cummins Engine Filters collection. For technical guides on this engine, see our Cummins ISX fuel filter cross-reference and the step-by-step replacement procedure.