The oil filter number for the 2018 Ram 2500/3500 with the 6.7L Cummins is Fleetguard LF3671.
In 2018, Ram’s 6.7-liter Cummins turbodiesel uses a spin-on oil filter that’s designed to meet OEM specifications. Fleetguard LF3671 is the commonly recommended replacement by many parts retailers and service shops. While you may see alternative cross-reference numbers from Wix, Baldwin, Mahle and other brands, LF3671 remains the standard for this engine family.
What fits the 2018 6.7 Cummins?
To ensure you’re using the correct filter for your vehicle, start with LF3671 and verify compatibility with your retailer or the Ram/Mopar parts catalog. You can cross-reference with other brands but you should always confirm that the part is intended for the Cummins ISB 6.7L engine and matches your model year.
Additional notes
When ordering, provide your vehicle’s year, make, model, sub-model, and engine type (ISB 6.7) to avoid mismatches. For owners who perform DIY maintenance, replacing the filter at regular intervals—per the owner's manual or dealership guidance—helps maintain engine cleanliness and longevity.
Summary
The Fleetguard LF3671 is widely accepted as the oil filter number for the 2018 Ram 2500/3500 with the 6.7L Cummins engine. If in doubt, check the official Ram/Mopar parts catalog or consult a trusted parts retailer to confirm compatibility based on your VIN.