Mann-Filter CUK 2939 Cabin Filter With Activated Charcoal

CUK 2939 is the OE-equivalent cabin filter for the Audi B7 A4 (2005–2008), B8 A4 (2009–2016), 8T A5 (2008–2016), and 8R Q5 (2009–2017), plus the S4, S5, and RS5 variants built on those chassis. It does NOT fit the earlier B6 A4 (2002–2004), which uses a different HVAC housing. Despite some third-party cross-reference databases listing it incorrectly, CUK 2939 is not the correct part for Toyota, Honda, Mercedes, or BMW vehicles. Always confirm chassis generation by VIN before ordering.

CUK is Mann-Filter's structural catalog designation for a cabin filter with an activated charcoal layer. The non-charcoal version of the same part exists separately as CU 2939 (ASIN B001DRLPJE). Because the charcoal layer is a part-number distinction rather than a marketing add-on, the carbon content of CUK 2939 is confirmed by the SKU itself, not just by listing copy.

No published EN 1822, ISO 16890, or ASHRAE 52.2 MERV test result is cited on the Amazon listing for CUK 2939 specifically. Mann+Hummel publishes general efficiency claims for the CUK series at the brand level, but no part-number-level test report is available in the listing data. The filter is treated as OE-equivalent on the strength of the original-equipment fitment pedigree and the structurally confirmed activated-charcoal layer.

Audi and VW OE service schedules for this filter are typically 12 months or about 12,500 miles, whichever comes first. The Amazon listing does not state a fixed mileage interval; Mann-Filter category guidance for cabin filters is the standard 12-month cycle. Drivers in dusty or high-pollen environments may benefit from a shorter interval.

Yes. Activated charcoal granules adsorb a broad range of volatile organic compounds and odors at the molecular level. Baking-soda impregnation neutralizes some acidic odors but does not deliver equivalent VOC adsorption. The CUK 2939 uses activated charcoal granules embedded in a carrier layer — the broader-capability technology of the two.