The K&N 33-2231 high-flow air filter is reusable and washable, featuring multiple layers of cotton gauze treated with a special bonding agent to trap contaminants. Its design aims to improve airflow and increase horsepower and acceleration. It comes pre-oiled and fits in the factory air box.
Under normal highway driving conditions, it needs to be cleaned every 120,000 km.
- Type: High-flow air filter
- Construction: Multiple layers of cotton gauze
- Reusable: Washable
- Preparation: Pre-oiled
- Compatibility: BMW E36, E46, E91, X3, 3 Series