K&N High-Flow Air Filter BMW M340i (G20/G21) & M440i (G22/G23) B58 3.0L

K&N High-Flow Panel Air Filter for BMW M340i (G20/G21) & M440i (G22/G23) – B58 3.0L

Part No: 33-3136  Quantity Required: 1 (Filters are sold individually)

Your G20 M340i or G22 M440i is everything a modern BMW should be – sharp, brutally fast in the real world and powered by the incredible B58 3.0-litre turbo straight-six. But even this engine is still trying to breathe through a restrictive, disposable paper filter designed around cost and emissions, not enthusiasts.

It’s time to let the B58 breathe properly. The K&N High-Flow Panel Air Filter is the ideal “first mod” for any M340i or M440i. It’s a direct drop-in replacement for the factory paper element, engineered to improve airflow, sharpen response and support more power – while being the last air filter you’ll ever need to buy for the car.

Using K&N’s multi-layered, oiled cotton gauze, this filter flows significantly more air than the stock paper filter while still providing excellent filtration. In the real world, that means a more eager throttle, stronger mid-range surge and a crisper induction note when you lean on that straight-six.

Unlike the disposable OEM filter, the 33-3136 is fully washable and reusable. When it gets dirty, you simply clean and re-oil it using a K&N service kit and refit – no more throwing away money on new filters at every service.

Key Features & Benefits

• Unlocks Performance: Increased airflow to your B58 3.0L turbo engine, helping to support gains in horsepower and torque over the restrictive OE paper filter.

• Sharper Throttle Response: Noticeably more eager pick-up and improved turbo spool, especially in the mid-range where you spend most of your time on the road.

• Reusable, Long-Life Design: Fully washable and reusable – clean, re-oil and refit instead of replacing, saving you money over the lifetime of the vehicle.

• Direct Drop-In Replacement: Designed to fit perfectly into the standard airbox on G20/G21 M340i and G22/G23 M440i models – no cutting, drilling or extra hardware required.

• Excellent Engine Protection: Multiple layers of oiled cotton gauze create a dense filtration mesh that captures harmful particles while still flowing far more air than paper.

• Extended Service Intervals: Under normal road use, the filter can go up to around 50,000 miles between cleanings, depending on driving conditions.

• Ideal Supporting Mod for Tuning: Perfect partner for Stage 1 and Stage 2 ECU remaps, exhaust and intercooler upgrades – removing a key restriction from the intake side.

MSL Recommends

Your B58 engine uses a single panel filter in the factory airbox, so you only need one (1) of these filters per car.

We especially recommend this upgrade if:

• You’re planning or already running a remap on your M340i or M440i.

• You want a simple, OEM-style upgrade you can feel every day, with no extra noise or “boy racer” look under the bonnet.

For best results and longevity, we also recommend keeping a K&N cleaning and re-oil kit so you can service the filter correctly and keep it performing at its best for the life of the vehicle.

Full Vehicle Fitment List

This K&N High-Flow Panel Air Filter (33-3136) is designed for a wide range of modern BMW G2x models, including all B58-powered M Performance 3 and 4 Series variants that share the same factory airbox, such as:

BMW 3 Series – G20 / G21

• M340i xDrive Saloon (3 Series, G20) – B58 3.0L

• M340i xDrive Touring (3 Series, G21) – B58 3.0L

• M340i Mild-Hybrid xDrive Saloon & Touring – B58 3.0L

BMW 4 Series – G22 / G23 / G26

• M440i xDrive Coupé (4 Series, G22) – B58 3.0L

• M440i xDrive Convertible (4 Series, G23) – B58 3.0L

• M440i xDrive Gran Coupé (4 Series, G26) – B58 3.0L

If you’re ever unsure whether this is the correct filter for your specific car (model year, engine or variant), just get in touch with your registration or VIN and we’ll happily confirm compatibility before you order.