The BMW X4 M40i stands out in the performance SUV segment, largely thanks to its potent engine. Discussions among automotive enthusiasts often revolve around the specifics of this powerplant, particularly when comparing it to engines found in other BMW M Performance models like the M2. One point of interest, highlighted in online forums, is the “closed deck” design of the engine block in the X4 M40i. Let’s delve into the details and clarify some of the questions surrounding this topic.
Initial information from official BMW sources suggested a “closed-deck design” for the engine in the X4 M40i. A U.S. press release from October 1, 2015, for the X4 M40i explicitly mentions this feature when describing the newly developed M Performance TwinPower Turbo inline 6-cylinder gasoline engine. According to the release, this design, where the water jacket surrounding the cylinders is sealed at the top, contributes to an exceptionally high degree of crankcase stiffness. This is a characteristic often associated with high-performance engines, aimed at enhancing durability and performance under stress.
Alt text: BMW X4 M40i engine bay showcasing the TwinPower Turbo inline 6-cylinder engine.
Interestingly, the US press release for the BMW M2, issued shortly after on October 14, 2015, also referenced a “closed deck” design for its engine. Both releases, around the same period, seemed to confirm this feature for both the X4 M40i and the M2, suggesting a shared engine architecture in this aspect.
However, a subsequent German press release for the X4 M40i, dated February 17, 2016, and an updated German press release for the M2 from the same date, presented a change. These later releases omitted any mention of the “closed deck” design. The description shifted to emphasize the engine’s lightweight, thermodynamically optimized aluminum construction, designed for maximum revving capability and powerful torque, blending driving dynamics with efficiency. This update raises questions about the initial claims and whether there was a change in engine specification or simply in the descriptive language used in the press materials.
Alt text: Side view of the BMW X4 M40i performance SUV highlighting its sporty design.
Despite the differing descriptions in press releases, the core engine in question is the N55B30T0. This engine is part of BMW’s N55 engine family, known for its TwinPower Turbo technology, combining a twin-scroll turbocharger with direct injection and Valvetronic variable valve lift. The “T0” designation often indicates specific tuning and performance enhancements applied by BMW’s M Performance division. Whether the engine block is technically a “closed deck” or a variation thereof, the N55B30T0 in the X4 M40i is engineered to deliver robust performance figures suitable for an M Performance vehicle.
In conclusion, while initial press releases pointed to a “closed deck” design for the BMW X4 M40i engine, later releases removed this detail. Regardless of the exact terminology or minor variations in engine block construction, the BMW X4 M40i utilizes the powerful and refined N55B30T0 engine. This engine is designed to provide the performance and driving experience expected from a vehicle bearing the M Performance badge, making the X4 M40i a compelling choice in its class. The discussion highlights the importance of verifying information across different sources and understanding that specifications can sometimes be nuanced in automotive manufacturing and marketing materials.
