Performance Air Filter for Audi A8 S8 4.0L 4.2L FSI 6.3L FSI W12 Engines

Sharper Induction for the Audi A8 & S8 (4H Chassis) | CEUA, CDRA, & CEJA Powerplants

Who It’s For: Engineered for the Audi D4 (4H) enthusiast running the high-output 4.2L FSI, the massive 6.3L W12, or the twin-turbocharged 4.0T S8. This is for the driver who wants their flagship sedan to breathe without the suffocating restrictions of factory paper elements.

The Symptom: The factory intake system on the [CEUA/CDRA/CEJA] engine family is designed primarily for sound suppression and long service intervals. To keep the cabin silent, Audi uses thick, pleated paper filters that create significant surface tension and air-path resistance. As these filters collect debris, they become a literal bottleneck, increasing pumping losses and softening the throttle response on a car that already weighs over 4,500 lbs. When you’re asking for 500+ horsepower, you don’t want your turbos or intake valves fighting a straw.

The Engineering Fix: This BMC Performance Filter replaces that restrictive paper with multi-layered cotton gauze treated with low-viscosity oil. By moving from a 10-micron filtration standard to a 7-micron standard, we actually increase the filtration efficiency while simultaneously widening the effective surface area for airflow. The "Full Moulding" construction ensures the filter frame is a single piece with no welded joints, meaning it won’t crack or leak under the high heat cycles found in the cramped A8 engine bay. This results in a more immediate torque delivery and a subtle, sophisticated increase in induction sound.

Why Mechanics Choose This Kit

• Optimized Fluid Dynamics: The epoxy-coated alloy mesh maintains the filter’s structural integrity even under the high-vacuum demands of the S8’s twin-turbochargers, preventing filter collapse.
• Sustainable Performance: Unlike OEM filters that go in the trash, these are fully washable and regenerable, designed to last the entire lifespan of your A8.
• Precision Fitment: Developed specifically for the 4H airbox, ensuring a perfect airtight seal to prevent "dirty air" bypass that can damage sensitive Mass Air Flow (MAF) sensors.

Technical Specifications

Compatibility & OEM Reference

Fits the Following Vehicles (Note: These engines utilize a dual-intake system and require 2 filters):

• Audi A8 (4H) 4.2 FSI [372 HP] (2009 - 2012)
• Audi A8 (4H) 6.3 FSI W12 [500 HP] (2011 - 2018)
• Audi A8 (4H) S8 4.0 [520 HP] (2012 - Current)
• Audi A8 (4H) S8 4.0 [605 HP] (2015 - Current)

Interchange Part Numbers:

FB877/08, 4H0129620D, 4H0129620L, 87708

The Performance Promise

Buy with confidence. As specialists in European performance, we know that your Audi deserves parts that match its engineering pedigree. We provide technical support and fast shipping to ensure your 4H is back on the road with the flow it needs. Important Tech Note: These high-capacity engines use a symmetrical air intake design; ensure you order two units for a complete service.