Air Intake Filters for BMW E21 320i M10 1.8L

Universal High-Flow Air Filter

Give your engine the airflow it deserves with this reusable, high-performance air filter—perfect as a direct replacement for an ECS intake system or as the finishing touch for your custom intake project.
Dimensions: 4.5" Base OD • 6" Filter Height • 3.5" Top OD

Upgrade from your restrictive factory filter to an ECS Tuning High-Flow Dry Air Filter and let your engine breathe freely. Improved intake flow enhances power throughout the rev range while helping maintain efficient fuel economy.

Oiled vs. Dry Filters — Which Is Right for You?

Oiled Filters

Offer slightly higher airflow for maximum performance

Require more frequent cleaning

Must be re-oiled after each cleaning

Long-term reusable design saves money over disposable paper filters

Dry Filters

Provide excellent airflow with minimal maintenance

Easily cleaned with warm, soapy water—no oiling required

Still flow significantly better than OE paper filters

Fully reusable and cost-effective

Both versions deliver superior performance over stock filters while offering the long-term benefit of reusability. Choose the option that best fits your maintenance style and performance goals.

K&N's drop-in air intake filter is constructed from cotton gauze material between aluminum mesh - this makes for a long lasting, high performance drop-in intake filter. These are very easy to remove and maintain. Turner Motorsport recommends this as one of the first maintenance/modifications you make to your vehicle after you purchase! 

K&N's drop in air filters allow increased airflow - dirt and particles stick to the oil on these filters, making them more effective than traditional paper filters in terms of protection. Additionally, K&N believes their filters are more efficient than paper filers - this means more oxygen getting into the engine, allowing vaporized fuel to burn more efficiently and increasing horsepower and fuel economy. The best of both worlds!

• Covered by the K&N Million Mile Limited Warranty
• Washable and reusable
• Emissions legal in all 50 states
• Will not void vehicle warranty

Since 1999, aFe (Advanced FLOW Engineering) has been developing and manufacturing high quality accessories in their facility in Corona, California. Starting with air filters and intake systems, and now expanding into exhaust systems, suspension components, tuning modules, and more, aFe products are a great way to improve the performance of your BMW without altering its fundamental character. Owned by a BMW enthusiast, aFe power is recognized the world over as a leader in quality performance products for your BMW.

• Constructed with 100% polyurethane
• Five layers of progressively finer mesh cotton gauze media
• Washable and reusable for multiple cleaning cycles
• Excellent dust-holding capacity for a longer service cycle between cleanings
• Integrated urethane bump seal insures a tight, no leak seal
• Outflows stock paper filter for improved horsepower and torque

This is a drop-in stock replacement aFe performance air filter that installs into your BMW's factory airbox. This particular filter fits the following BMWs:
E30 M3 (1988-1991)
E30 318i (1984-1985)
E28 528e (1984-1985) and 535i/535is (1985-1988)
E12 5 series, All (1975-1981) - including 528i, 530i, 533i
E23 7 series, All except 745i (1977-1987) - including 730i, 733i, 735i, L7
E24 6 series, All except M6 (1976-1989) - incl. 630CS, 633Csi, 635CSi


This version uses aFe's highest flowing filter media, which uses a lightly oil gauze to filter out dirt and particulates, while allowing more air to flow to the intake. For the best flowing filter, with the best performance gain, we always recommend this standard aFe filter media (often called "Pro5R ", which has a blue pre-oiled filter media). We also carry this filter in the "ProDry" grey filter media, which is oil-free for only slightly less performance and no maintenance.