ITG WB-385 performance panel air filter for BMW

Upgrade your BMW's original air filter with the ITG ProFilter WB-385. This replacement foam element fits inside the compatible factory airbox, providing a reusable alternative to the standard disposable paper filter.

The original airbox and intake ducting remain in place, making the WB-385 a straightforward filter upgrade without fitting a complete induction kit.

Multi-layer foam filtration

ITG's Trifoam construction uses multiple foam layers to capture airborne dirt while maintaining airflow. Combined with the appropriate dust-retention oil, the foam provides filtration throughout its depth and a high capacity for holding dirt.

Product features

• Genuine ITG ProFilter, part number WB-385
• Replacement panel filter for compatible original BMW airboxes
• Multi-layer foam filtration
• Washable and reusable
• Handmade in Britain
• Filter size: 227 × 203 mm

Keep the original airbox

The WB-385 replaces the filter element while retaining the vehicle's original airbox. It is suitable for customers wanting a serviceable performance filter without changing the complete intake system.

Cleaning and maintenance

Clean and re-oil the filter using ITG-approved foam filter products. Allow it to dry completely after cleaning before applying the appropriate foam filter oil.

ITG recommends cleaning ProFilter panel elements every 16,000 km and inspecting them at least every 12 months. Inspect and service the filter more frequently in dusty conditions.

Do not use cotton-gauze filter oil or engine oil. Avoid compressed air and heat guns when drying the foam.

Scope of delivery:

• 1x ITG ProFilter WB-385 replacement air filter

Check your application

BMW used different airboxes across these model ranges. Confirm that your vehicle uses the 227 × 203 mm filter arrangement before ordering.

The WB-385 is not suitable for M135i or M235i applications. Later petrol models using the larger five-sided filter require a different element. See the fitting note for further exclusions.

Why choose foam?

Because, compared to paper or other filter technologies, reticulated polyester foam achieves optimum performance against three key criteria:

• Maximum airflow: the ability to allow air to pass through without causing a large drop in pressure.
• Cleaning efficiency: the capability to arrest a high proportion of airborne dust while feeding the engine clean air.
• Dust load-up tolerance: the capability to absorb a large amount of dust without reducing airflow capacity.

This design of filter has been used in all fields of motorsport from Formula 1 to the World Rally Championship. The range receives this same attention to detail at the design stage and is then taken into production with consummate quality.

Three layer foam system in details:

ITG ProPanel Filters use multi-layered foam technology to trap dust and dirt while maintaining flow efficiency over time. Using foam increases the filters surface area and is washable, compared to standard paper and cotton filters which trap dust on the surface and become less efficient the more they are used, choking the engine and reducing performance.

The outer core is a coarse foam designed to trap larger particles, the second layer is a medium foam designed to trap most particles and the inner core is fine foam which will trap any particles small enough to reach it. The triple layer foam design ensures an exceptional level of engine protection and long-term performance advantage.

1. Stainless steel wire mesh
   To avoid erosion, only the highest quality steel is used.
2. Course outer layer:
   Stops large pieces of dirt and foreign matter from penetrating further. Straightens airflow into subsequent layers.
3. Medium grade middle layer:
   This second filtration layer traps most of the harmful dirt that leads to engine damage.
4. Fine inner layer:
   Extracts fine particles while allowing full air flow to the engine for maximum power.