Mercedes-Benz is set to revolutionize its flagship S-Class sedan with a surprising engine choice: a flat-plane crank V-8, typically reserved for high-performance sports cars. This marks the first time a luxury sedan will feature such an engine, and the shift is driven by a combination of emissions compliance and performance optimization.
The V-8 Crankshaft Debate: Flat-Plane vs. Cross-Plane
For decades, luxury sedans have relied on cross-plane crankshaft V-8 engines. These engines deliver a deep rumble, high torque, and balanced operation, making them ideal for heavy vehicles. However, the move towards stricter emissions standards has prompted Mercedes-Benz to explore alternative configurations. Flat-plane cranks, favored by sports cars like Ferraris, are lighter, higher-revving, and produce a sharper exhaust note. Their inherent imbalance traditionally made them unsuitable for luxury vehicles, but modern engineering has overcome these challenges.
Why Now? Emissions and Efficiency
Mercedes-Benz cites improved exhaust scavenging as the primary reason for the switch. Flat-plane cranks facilitate more efficient exhaust gas removal, resulting in cleaner emissions. This decision is further supported by the inclusion of a 48-volt mild-hybrid system, enhancing overall efficiency. The new M177 Evo engine, a 4.0-liter V-8, produces 553 lb-ft of torque, available from just 2,200 RPM, rivaling the performance of traditional cross-plane designs.
Balancing Act: Performance and Luxury
To mitigate the flat-plane crank’s natural vibrations, Mercedes-Benz has integrated balance shafts into the M177 Evo. Despite the engine’s high-revving potential, the automaker has focused on noise reduction and refinement, ensuring a smooth and quiet ride experience. The result is a V-8 that blends the responsiveness of a flat-plane crank with the torque-rich characteristics of a cross-plane design.
The 2027 S-Class: Tech-Heavy Transformation
Beyond the engine, the 2027 S-Class receives a comprehensive redesign, with over 50% of the vehicle being new. The interior features an expansive MBUX Superscreen, incorporating three displays powered by the MB.OS operating system. While the removal of tactile materials has been compensated by wood accents, some critics question the practicality of electronically controlled air vents. Other tech upgrades include ChatGPT4o-powered voice assistance, executive rear seats with touchscreens, and a Burmester 4D surround sound system with 39 speakers.
The exterior design also reflects Mercedes-Benz’s branding strategy, with a larger illuminated grille and the three-pointed star logo prominently integrated into the headlights and taillights.
The 2027 Mercedes-Benz S-Class represents a bold step towards combining high-performance engine technology with luxury refinement. This move not only addresses emissions concerns but also sets a new standard for innovation in the full-size luxury sedan segment.
