K&N 33-2125 High-Flow Air Filter for 1994-2009 Audi A4 A6 S4 S6 RS4 VW Passat

Vehicle Fitment

• 1994-2001 Audi A4 / B5 (All Trims, 1.6L / 1.8L / 1.8T / 2.4L / 2.6L / 2.8L, FWD)
• 1996-2005 Audi A4 Quattro / B5 & B6 (All Trims, 1.8T / 2.4L / 2.8L / 3.0L, AWD)
• 1997-2005 Audi A6 / C5 (All Trims, 1.8L / 2.4L / 2.7L / 2.8L / 3.0L / 4.2L, FWD)
• 1997-2005 Audi A6 Quattro / C5 (All Trims, 2.4L / 2.7L / 2.8L / 3.0L / 4.2L, AWD)
• 2000-2003 Audi S4 / B5 (All Trims, 2.7L Biturbo, AWD)
• 2000-2001 Audi RS4 / B5 (All Trims, 2.7L Biturbo, AWD)
• 2002-2004 Audi S6 / C5 (All Trims, 4.2L V8, AWD)
• 2001-2005 Audi Allroad Quattro / C5 (All Trims, 2.5L TDI / 2.7L Biturbo / 4.2L V8, AWD)
• 1996-2009 Volkswagen Passat / B5 & B5.5 (All Trims, 1.6L / 1.8T / 1.9L TDI / 2.0L / 2.3L V5 / 2.5L / 2.8L / 4.0L W8, FWD & 4MOTION)
• 2001-2008 Skoda Superb / 3U (All Trims, 1.8T / 1.9L TDI / 2.0L / 2.5L TDI / 2.8L V6)

Fitment Notes

• Audi A4 B5 fitment covers both FWD and Quattro AWD variants across 1.8T, 2.4L, 2.6L, and 2.8L engines
• Audi A4 B6 Quattro fitment confirmed for 3.0L V6 variant (2001-2005) only
• Audi RS4 fitment is for the B5 generation (2000-2001) 2.7L Biturbo only; does not fit the B7 RS4
• Volkswagen Passat 2009 fitment applies to select carry-over B5.5 variants - verify build date before ordering
• Skoda Superb fitment covers the 3U / B5-platform generation (2001-2008) only
• Does not fit Audi A4 B7 (2005+) or A6 C6 (2005+) - these require a different filter

Features

• Drop-in replacement - installs directly into the factory airbox with no modifications
• 4-layer oiled cotton gauze media for high airflow and reliable contaminant capture
• Engineered to increase horsepower and acceleration over stock paper filters
• Pre-oiled and ready to install straight out of the box
• Washable and reusable - cleaning interval every 75,000 miles under normal conditions
• Compatible with OEM airbox and factory MAF sensors - no recalibration required
• Reduces long-term filter replacement costs and environmental waste
• Backed by K&N's No-Hassle Lifetime Limited Warranty

Specifications

• Part Number: 33-2125
• Filter Style: Panel Air Filter (Open Top)
• Filter Media: Oiled Cotton Gauze
• Outside Length: 9.875 in (251 mm)
• Outside Width: 8.25 in (210 mm)
• Height: 0.75 in (19 mm)
• Filter Re-Oiling Amount: 1.32 oz (39 ml)
• Weight: 1.1 lb (0.5 kg)
• Inner Wire Support: No
• Compatible Engine Sizes: 1.6L, 1.8L, 1.8T, 1.9L TDI, 2.0L, 2.3L V5, 2.4L, 2.5L TDI, 2.6L, 2.7L Biturbo, 2.8L, 3.0L V6, 4.0L W8, 4.2L V8
• Washable: Yes
• Warranty: No-Hassle Lifetime Limited

Included Components

• 1x K&N 33-2125 High-Flow Panel Air Filter

Product Description

The K&N 33-2125 is a washable, reusable drop-in replacement air filter engineered for a broad range of Audi, Volkswagen, and Skoda vehicles built on the B5/C5/3U VAG platform - covering the Audi A4, A6, S4, S6, RS4, Allroad Quattro, Volkswagen Passat, and Skoda Superb. Spanning an extensive engine range from the 1.6L petrol and 1.9L TDI diesel through to the 2.7L Biturbo and 4.2L V8, this filter drops directly into the factory airbox without modification and is fully compatible with OEM MAF sensors. Its 4-layer oiled cotton gauze construction delivers significantly more airflow than a stock paper filter while maintaining reliable engine protection.

Only needing cleaning every 75,000 miles, the K&N 33-2125 is a practical lifetime upgrade for one of the most widely sold VAG platform families. Whether fitted to a daily-driven Passat 1.9 TDI, a tuned S4 Biturbo, or an Allroad Quattro, this filter delivers improved throttle response and airflow across all supported applications.