The BMW X4 M40i, a performance-oriented SUV, shares engine lineage with the acclaimed M2. Initial reports and press releases suggested a strong similarity between their power plants, specifically mentioning the N55B30T0 engine code. One particular point of interest was the “closed-deck” engine design, touted for its enhanced stiffness and performance capabilities. However, a closer examination of official BMW documentation reveals an intriguing discrepancy regarding this feature in the X4 M40i.
Early press releases from BMW in October 2015 for the US market explicitly stated the X4 M40i engine incorporated a closed-deck design. These releases, coinciding with the initial M2 announcements, highlighted the robust construction method where the water jacket surrounding the cylinders is sealed at the top. This design is known to enhance crankcase stiffness, crucial for high-performance engines. The US press release emphasized this feature as a key element of the newly developed M Performance TwinPower Turbo inline 6-cylinder gasoline engine in the X4 M40i.
However, a subsequent German press release for the X4 M40i, issued in February 2016, alongside an updated M2 release on the same day, omitted any mention of the closed-deck design. This update removed the specific wording describing the sealed water jacket and instead focused on the engine’s responsiveness and efficiency. The absence of the “closed-deck” reference in the later German release raises questions about the consistency of BMW’s communication regarding the X4 M40i engine specifications.
This change in official communication prompts further investigation. Did BMW subtly alter the engine design between the October 2015 and February 2016 press releases? Or was the initial mention of a closed-deck design in the X4 M40i US press release an oversight or miscommunication? The differing descriptions across press releases, particularly the removal of the “closed-deck” detail in the German update, leaves enthusiasts and potential owners seeking clarification on the exact engine construction of the BMW X4 M40i. Understanding the precise engine architecture is vital for those interested in performance tuning, maintenance, and long-term ownership of the X4 M40i.
