MMX Baffled oil sump | BMW N55 F2x & F3x | M135i | M235i | 335i | 435i

MMX Baffled Oil Sump – BMW N55 F2X & F3X

Protect your N55 engine from oil starvation during hard driving with the MMX Baffled Oil Sump.

Designed for rear-wheel-drive BMW F2X and F3X models including the M135i, M235i, 335i and 435i, the MMX sump incorporates a sophisticated internal baffle system developed to control oil movement and maintain a more consistent supply to the oil pickup.

For cars used on track or driven particularly hard on the road, this is a valuable reliability-focused upgrade designed to reduce the risk of oil surge and the potentially severe engine damage that can follow.

Why Upgrade the N55 Oil Sump?

The N55 can experience oil starvation under sustained high-G driving.

Under heavy braking and cornering, engine oil can move aggressively inside the sump.

If enough oil moves away from the pickup, the oil pump can temporarily draw air rather than lubricant.

Even a brief loss of oil pressure can place critical engine components at risk.

The MMX baffled sump is engineered specifically to reduce this oil movement and maintain a more consistent supply around the pickup.

Key Features

• MMX baffled oil sump for BMW N55
• Designed for F2X and F3X chassis
• Developed for hard road and track use
• Helps reduce oil surge
• Helps maintain more consistent oil pressure
• Seven one-way oil-control flaps
• Dedicated internal baffling
• T-6061 anodised aluminium construction
• Direct bolt-in design
• No welding required
• Extensively road and track tested
• Designed to protect engine longevity
• Suitable for performance and track-focused builds
• Rear-wheel-drive applications only
• Does not fit xDrive models
• MMX part number MMR20-0501

Designed to Combat N55 Oil Starvation

The main purpose of the MMX sump is to help prevent oil starvation during high-load driving.

When the car is subjected to aggressive braking or cornering forces, oil can surge away from the pickup area.

The MMX baffling system is designed to control that movement and keep a greater volume of oil around the pickup.

This helps maintain more stable lubrication when the engine is under the greatest stress.

Seven One-Way Oil-Control Flaps

The sump uses seven one-way oil-control flaps.

These are designed to allow oil to move toward the pickup area while restricting its ability to surge away under acceleration, braking or cornering.

This creates a more controlled oil environment inside the sump.

The result is improved oil retention around the pickup during dynamic driving.

Dedicated Internal Baffling

Alongside the one-way flaps, the sump uses carefully positioned internal baffles.

These help divide and control the oil volume within the sump.

The combination of baffles and one-way flaps is designed to reduce uncontrolled oil movement far more effectively than the standard sump arrangement.

Helps Maintain Oil Pressure

Stable oil pressure is critical to engine reliability.

If the pickup is briefly uncovered, oil pressure can drop.

That reduction in pressure can affect lubrication to important components such as:

• Crankshaft bearings
• Connecting rod bearings
• Camshaft components
• Turbocharger bearings
• Timing components

The MMX sump is designed to help maintain a more consistent oil supply during conditions where the standard setup may struggle.

Particularly Important Under Hard Braking

MMX specifically highlights heavy braking as one of the situations where the N55 can suffer oil-control problems.

Under strong deceleration, oil can move forward inside the sump.

If enough oil leaves the pickup area, lubrication can be compromised.

The MMX baffle system is designed to keep oil where it is needed even under these high longitudinal loads.

Ideal for Track Cars

The MMX Baffled Oil Sump is particularly suited to N55-powered cars used for:

• Track days
• Fast-road driving
• Time Attack
• Sprint events
• Hill climbs
• Motorsport
• High-grip tyre setups
• Repeated hard braking

Track driving exposes the engine to sustained lateral and longitudinal forces that are difficult to replicate during normal road use.

This is where improved oil control becomes most valuable.

Important for High-Grip Tyres

As tyre grip increases, the car can generate greater cornering and braking forces.

That increased grip also increases the forces acting on the oil inside the sump.

Cars running:

• Semi-slick tyres
• Track-focused road tyres
• Wider performance tyres
• Aggressive suspension setups

can therefore place even more demand on the engine lubrication system.

For these builds, a baffled sump becomes an especially sensible supporting modification.

Road Use Benefits

The MMX sump is not only for dedicated track cars.

Hard road driving can also generate strong oil movement, particularly during:

• Heavy braking
• Long sweeping corners
• Rapid direction changes
• Mountain-road driving
• High-speed performance use

For heavily modified or frequently driven N55 cars, the sump provides additional lubrication protection even if the vehicle only sees occasional circuit use.

Bolt-In Design

Unlike some aftermarket baffling solutions that require a plate to be welded into the original sump, the MMX system is designed as a bolt-in solution.

This makes installation considerably more straightforward and accessible.

Benefits include:

• No welding required
• Cleaner installation
• More consistent fitment
• Easier workshop installation
• Purpose-designed complete solution

T-6061 Aluminium Construction

The MMX sump baffle is manufactured from anodised T-6061 aluminium.

This provides:

• Low weight
• High strength
• Good corrosion resistance
• Precise fitment
• Durability under demanding conditions

The anodised finish also provides additional surface protection for long-term use.

Extensively Road & Track Tested

MMX states that the baffled sump has been tested over thousands of miles of road and track use.

The internal design was developed and validated using data collected during testing.

This makes it a purpose-developed N55 oil-control solution rather than a generic universal baffle.

Reliability-Focused Upgrade

The MMX sump is fundamentally a preventative reliability upgrade.

It does not directly add horsepower.

Instead, it is designed to help protect the engine when it is subjected to the conditions that create the greatest lubrication risk.

For hard-driven N55 cars, avoiding oil starvation can be far more valuable than a small increase in peak power.

Ideal Supporting Upgrade for Tuned N55 Engines

Tuned N55 engines can produce significantly more power and torque than standard.

Although increased power does not itself cause oil surge, modified cars are often driven harder and fitted with:

• Stickier tyres
• Upgraded suspension
• Bigger brakes
• Additional cooling
• Track-focused components

These upgrades allow the car to generate higher sustained forces, increasing the importance of good oil control.

Baffled Sump vs Standard Sump

The standard sump is designed around typical road use.

The MMX baffled sump adds:

• Seven one-way oil flaps
• Additional internal control
• Improved oil retention around the pickup
• Greater protection during sustained high-G driving

For a standard road car driven gently, the factory system may be sufficient.

For cars used aggressively, the MMX sump offers a significant increase in oil-control capability.

Baffled Sump vs Accumulator or Dry-Sump Systems

More complex lubrication solutions can provide even greater protection.

These may include:

• Oil accumulators
• Dry-sump systems
• External oil-management systems

However, these systems are more expensive, more complex and often unnecessary for road and track-day builds.

The MMX baffled sump provides a much simpler bolt-in solution while retaining the factory-style lubrication architecture.

BMW F20 / F21 M135i

The MMX Baffled Oil Sump is compatible with rear-wheel-drive BMW F20 and F21 M135i models equipped with the N55 engine.

For track-focused M135i builds, the sump provides an important layer of protection against oil surge under hard driving.

BMW F22 / F23 M235i

The sump is suitable for rear-wheel-drive BMW F22 M235i Coupe and F23 M235i Convertible models with the N55 engine.

It is particularly valuable on cars running upgraded suspension, tyres and brakes for track use.

BMW F30 / F31 335i

The MMX sump is compatible with rear-wheel-drive BMW F30 and F31 335i models powered by the N55.

For modified fast-road or track-focused 335i builds, the improved oil control helps support engine reliability under sustained load.

BMW F32 / F33 435i

The kit is also suitable for rear-wheel-drive BMW F32 435i Coupe and F33 435i Convertible applications with the N55 engine.

The same seven-flap baffling system helps maintain oil supply during aggressive braking and cornering.

Rear-Wheel Drive Only

This product does not fit xDrive models.

The xDrive drivetrain uses a different front drivetrain and sump arrangement, so the MMX N55 baffled sump is intended only for compatible rear-wheel-drive F2X and F3X applications.

Please confirm drivetrain configuration before ordering.

Compatibility

Designed for compatible N55-powered rear-wheel-drive BMW applications including:

• BMW F20 M135i
• BMW F21 M135i
• BMW F22 M235i
• BMW F23 M235i Convertible
• BMW F30 335i
• BMW F31 335i Touring
• BMW F32 435i
• BMW F33 435i Convertible

MMX lists the application across F20, F21, F22, F23, F30, F31, F32 and F33 chassis from 2011–2020.

Important: Does not fit xDrive models.

Professional Installation Recommended

Oil sump work requires access beneath the engine and correct installation of the internal components.

Professional installation is strongly recommended unless you have appropriate mechanical experience.

Installation should include:

• Correct sump removal
• Thorough cleaning
• Proper installation of the MMX baffle
• Correct sealing procedure
• Correct torque sequence
• Fresh engine oil where required
• Leak checks after installation

Ideal Supporting Upgrades

For a track-focused N55 build, consider combining the MMX baffled sump with:

• High-quality performance engine oil
• Oil cooler upgrades
• Low-temperature oil thermostat
• Oil catch can
• Performance brake fluid
• Track brake pads
• Suspension upgrades
• Performance tyres

Reliable oil control should form part of a complete track-preparation package.

What's Included?

The MMX N55 Baffled Oil Sump package includes:

• MMX T-6061 anodised aluminium sump baffle assembly
• Seven integrated one-way oil-control flaps
• Required MMX-specific installation components

Please refer to the supplied fitting instructions for exact installation requirements.

Explore More BMW N55 Performance Parts

Looking to improve the reliability and performance of your N55-powered BMW further? Explore our range of engine and chassis upgrades.

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