The MMX Performance BMW Billet Oil Filler Cap is a precision-engineered upgrade designed to enhance both the appearance and functionality of your BMW engine bay. Compatible with BMW B58, N54, N55, S54, S55, and S63 engines, this cap replaces the factory plastic unit with a durable, high-quality billet solution that delivers lasting performance and a refined OEM+ aesthetic.

CNC-machined from a solid block of 6061 aerospace-grade aluminum, the MMX billet oil filler cap offers exceptional strength, heat resistance, and long-term durability. Each cap is finished in a deep gloss black anodizing, providing excellent corrosion resistance while maintaining a premium appearance that complements other engine bay upgrades.

Designed with both form and function in mind, this billet oil filler cap features an updated orientation system that allows installation in either a 0° or 90° position, ensuring proper logo alignment for both longitudinal and transverse engine layouts. An internal spring-loaded locking mechanism provides a positive “click” when fully seated, giving confidence that the cap is securely installed every time.

This secure locking design helps prevent common issues associated with aging factory caps, such as oil seepage and inconsistent sealing. The machined outer profile of the MMX billet filler cap provides enhanced grip, making oil top-ups and routine maintenance quicker and easier.

The MMX Performance BMW Billet Oil Filler Cap is a direct replacement for engines using the rounded factory cap design (OE part number 11128655331). Please verify compatibility by comparing the underside of your factory cap with the product images prior to installation.
Original factory oil filler cap seal must be reused.

Whether you’re completing an engine bay refresh or upgrading for long-term reliability, this billet cap delivers the fit, finish, and confidence expected from a premium BMW upgrade.

Key Features & Benefits:

CNC-machined 6061 billet aluminum construction

Gloss black anodized finish for durability and OEM+ appearance

Spring-loaded locking mechanism for secure fitment

Adjustable 0° or 90° orientation for proper alignment

Improved grip for easier installation and oil filling

Direct-fit replacement for compatible BMW engines