KAX Engine & Cabin Air Filter Kit for BMW CA11305 & CF11472 — Direct Fit, Activated Charcoal Cabin Filter

The KAX CA11305 & CF11472 kit is a two-piece replacement set containing an engine air filter and a cabin air filter engineered for select BMW models to restore engine airflow and improve in‑car air quality.

This kit pairs a high‑efficiency engine intake filter with a coconut shell activated‑charcoal cabin filter so you can handle two common maintenance items in a single purchase. Designed for direct fitment to specific BMW 2‑ and 4‑series and 3‑series variants, the set follows OEM form, fit and function guidelines to simplify installation and minimize guesswork. The combo replaces the factory parts at recommended service intervals and helps maintain consistent engine breathing while reducing odors and particulate in the passenger compartment.

Which BMW models does this KAX filter kit fit?

The kit is manufactured for compatibility with a range of BMW 2‑ and 4‑series and certain 3‑series variants. Confirm fit by comparing your vehicle’s original part numbers to the kit’s references before ordering.

• Compatible models include 320i, 320i xDrive, 328i xDrive, 328i GT xDrive, 328d xDrive
• Also fits 228i, 428i, 428i xDrive and 428i Gran Coupe variants
• Check chassis year and engine code against your OEM filter numbers

How do these filters improve everyday driving?

The engine filter preserves unrestricted airflow to the intake system and the cabin filter reduces airborne particulates and odors inside the car. Together they contribute to smoother throttle response and a fresher cabin atmosphere without altering vehicle systems.

• Engine filter traps dust and debris before entering the intake tract
• Coconut shell activated charcoal layer neutralizes odors and VOCs
• Multi‑layer media balances filtration efficiency with airflow

How easy is installation and routine maintenance?

Installation is straightforward and designed for a fast single‑person job using minimal tools. The two parts are separate replacements and install into their factory locations with existing clips and housings, allowing you to complete both in about five minutes when you know the access points.

• Swap engine air filter in the intake box—no cutting or trimming required
• Replace cabin filter behind glove box or under cowl per BMW layout
• Follow manufacturer recommended torque and reassembly steps for secure fit

When should I replace both filters?

KAX recommends changing the engine and cabin filters together to maintain consistent performance and in‑car air quality. Replacing them as a pair reduces the chance one worn component undermines the other.

• Suggested interval: every 12 months or 12,000 miles (whichever comes first)
• Replace sooner in dusty or heavy‑pollution environments
• Keep a combined spare to simplify future maintenance

Who is this for: This KAX CA11305 & CF11472 dual‑filter set is aimed at BMW owners who prefer practical, cost‑efficient maintenance—DIY enthusiasts, independent shop mechanics, and fleet managers who want a direct‑fit replacement for select 2‑ and 4‑series and compatible 3‑series variants. If you value preserving engine breathing and reducing in‑cabling odors and particulates without aftermarket modification, this kit gives you both components in one convenient purchase for synchronized upkeep.