You read that correctly. The world’s most prestigious luxury sedan just got a flat-plane crankshaft V8, and it did not come from Affalterbach. The 2027 Mercedes-Benz S580 4Matic uses the new M177 Evo — a comprehensively rebuilt 4.0-litre twin-turbocharged V8 with a flat-plane crank, revised injection, optimised intake and exhaust ports, improved turbochargers, and a new mild-hybrid system — producing 530 horsepower and 553 pound-feet of torque. Zero to 60 miles per hour takes 3.9 seconds. Professional testers who drove this engine on Baltic Sea roads and unlimited Autobahn called it strong, unrelenting, and borderline too aggressive for a non-AMG S-Class. Their words, not mine. And yes, that is a compliment.
Let me set the scene for the engineering nerd in the room, because the flat-plane crankshaft detail in a non-AMG Mercedes deserves a proper explanation before we talk about what it feels like and why it matters.
Flat-plane crankshafts have historically lived in two specific contexts: high-revving naturally aspirated Ferrari and Maserati engines where the firing order and balance characteristics allowed screaming redlines above 8,000 RPM, and certain AMG and performance applications where engineers wanted a specific exhaust note and a particular combustion rhythm. The traditional cross-plane crankshaft that Mercedes has used in its V8 engines for decades produces smoother, quieter power delivery at the cost of some acoustic character and a slightly more restricted rev ceiling.
For 2027, Mercedes decided to bring the flat-plane architecture to the standard S-Class lineup, not to chase high-revving drama, but to reduce rotating mass and internal vibration in a way that allows the engine to rev more freely, deliver power with greater immediacy, and meet increasingly strict Euro 7 emissions requirements simultaneously. That is not the exotic reason enthusiasts typically associate with flat-plane cranks. But the outcome in actual driving is closer to the exotic side than the regulatory compliance side, and that is what matters.
What the New M177 Evo Actually Delivers
The M177 Evo is not an entirely new engine. Mercedes has used the M177 4.0-litre twin-turbocharged V8 in AMG applications for over a decade, so the basic architecture has enormous development hours behind it. What the Evo designation signals is a comprehensive suite of refinements applied to a proven foundation.
The flat-plane crankshaft changes the firing order and reduces rotating mass in a way that Mercedes engineers describe as enabling the engine to rev more freely and deliver power with greater immediacy and refinement. New injection system hardware improves fuel atomisation. Optimised intake and exhaust ports improve breathing efficiency across the RPM range. Revised intake camshafts change the valve timing characteristics. Improved turbocharger specifications boost pressure delivery. A new mild-hybrid system adds low-RPM torque fill that eliminates any hesitation off idle.
The result is 530 horsepower and 553 pound-feet of torque. For context, the outgoing S-Class V8 produced 449 horsepower and 516 pound-feet. The Evo adds 81 horsepower and 37 pound-feet, significant gains from what are described as evolutionary rather than revolutionary changes to the engine architecture.
The zero to 60 time improves to 3.9 seconds, 0.4 seconds quicker than the outgoing V8’s result, which is a meaningful gain in real-world driving even if the S-Class’s primary appeal has never been stoplight performance. The electronically limited top speed is 155 miles per hour in standard configuration, with professional testers on unrestricted Autobahn stretches noting results closer to 158 miles per hour.
One professional reviewer who drove the S580 on a mix of Baltic Sea winding roads and unlimited Autobahn stretches described the experience with a specific phrase that lodged in my mind. The deep rumble of the flat-plane V8, they wrote, is borderline too aggro for a non-AMG S-Class, and they added immediately that this was not a complaint. That tension, the most prestigious non-performance sedan in the world producing a sound and a character that feels too intense for the category, is exactly the interesting story hiding inside the specification sheet.
The Three Powertrain Options and How They Compare
The 2027 S-Class updates the entire powertrain lineup, not just the V8. Understanding all three options clarifies exactly where the flat-plane V8 sits in the hierarchy.
The S500 4Matic uses the familiar twin-turbocharged 3.0-litre inline-six, producing the same 442 horsepower as before but with torque increased to 443 pound-feet, up approximately 30 pound-feet from the previous version. The overboost function briefly raises torque to 472 pound-feet when maximum acceleration is demanded. The S500 reaches 60 miles per hour in approximately 4.3 seconds, about two tenths quicker than last year’s equivalent, reflecting the torque improvement’s contribution to initial acceleration without powertrain architecture changes.
The S580e 4Matic is the plug-in hybrid, pairing the inline-six with an electric motor that adds 74 horsepower over its predecessor for a combined system output of 576 horsepower. Despite producing 46 more horsepower than the pure V8 S580, the PHEV takes approximately half a second longer to reach 60 miles per hour because of additional weight from the battery and hybrid hardware. Professional reviewers who drove the S580e describe it as every bit as nice to drive as the V8 version, with the same feeling of balance and composure, despite the power and weight trade-offs between the two configurations.
The S580 4Matic with the M177 Evo V8 is the clear star of the updated lineup on paper, and it proved to be the configuration that professional drivers chose to spend maximum time with when given free access to both models on press drives.
The Design Updates That Surprise With Boldness
Mercedes describes the 2027 S-Class as a mid-cycle update, but the company simultaneously acknowledges that more than fifty percent of the car is new, with approximately 2,700 parts changed or improved. That scope of change stretches the definition of facelift considerably.
The exterior updates are more visually assertive than S-Class refreshes have typically been. An illuminated hood ornament returns, a piece of old-world luxury symbolism that somehow feels entirely modern and appropriate when integrated into the 2027’s design language. Star-shaped daytime running lights form a distinctive front lighting signature that immediately identifies the new model from the previous generation. A larger grille with rows of tiny chromed three-pointed stars replaces the previous grille’s more restrained approach. Star branding integrates into the taillights as well, creating a consistent night signature at both ends.
The interior makes what is arguably the biggest structural change of the entire update. A giant slab of glass acts as the dashboard protection for three separate screens in a sweeping widescreen presentation that introduces the brand’s latest MB.OS software architecture. This is the most technologically significant interior change in the current S-Class generation, and the software advancement that accompanies it brings the S-Class’s connected car functionality to the current state of the art.
Read: AMG Listened! The 2027 Mercedes-AMG GLC53 Coupe Brings Back the 6-Cylinder
2027 Mercedes-Benz S-Class Powertrain Comparison Chart
| Specification | S500 4Matic | S580e 4Matic (PHEV) | S580 4Matic (V8) |
| Engine | 3.0L inline-six twin-turbo | 3.0L inline-six plus electric motor | M177 Evo 4.0L V8 twin-turbo |
| Crankshaft Architecture | Cross-plane | Cross-plane | Flat-plane (new for 2027) |
| Horsepower | 442 hp | 576 hp (combined) | 530 hp |
| Torque | 443 lb-ft | 553 lb-ft | 553 lb-ft |
| Overboost Torque | 472 lb-ft briefly | 553 lb-ft | Not separately specified |
| Zero to 60 MPH | Approximately 4.3 seconds | Approximately 4.4 seconds | 3.9 seconds |
| Torque Gain vs Previous | Plus 30 lb-ft | Plus 73 hp electric gain | Plus 37 lb-ft, plus 81 hp |
| Speed Gain vs Previous | Approximately 0.2 sec quicker | Similar to previous | 0.4 seconds quicker |
| Top Speed (standard) | 155 MPH electronically limited | 155 MPH electronically limited | 155 MPH electronically limited |
| Mild Hybrid | Yes | Full PHEV with electric motor | New mild-hybrid system added |
| Character | Smooth, quiet, linear | Most powerful, slightly slower | Most aggressive, fastest |
| Professional Driver Preference | Strong baseline | Equally nice to drive as V8 | Chosen first on press drives |
Why the Flat-Plane Crank in a Non-AMG Matters for Enthusiasts
Here is the broader significance of this engineering decision that I think deserves direct discussion.
Flat-plane crankshafts have always carried a specific cultural cachet in automotive enthusiast circles. They appeared in Ferraris. They appeared in the AMG GT Black Series. They represented a choice made for performance character rather than regulatory compliance or manufacturing convenience. When Mercedes installs a flat-plane crank in the standard production S-Class and grounds the decision partly in Euro 7 emissions compliance rather than purely in performance aspiration, it changes the cultural signal somewhat.
But the sound that comes out the back of the S580’s exhaust, and the character that the revised firing order and reduced rotating mass produce in the actual driving experience, does not feel like a regulatory concession. It feels like a deliberate choice to add acoustic drama and dynamic immediacy to the world’s most prestigious luxury sedan. The regulatory compliance motivation and the enthusiast outcome are not mutually exclusive, and the 2027 S580 is the specific example that proves they can coexist.
The AMG S63 will eventually receive its own version of this engine in a more extreme state of tune, paired with a plug-in hybrid system and expected to produce outputs that match or exceed its current extraordinary specification. When that happens, it will build on the M177 Evo foundation established first in the standard S-Class. For now, the S580 wears this technology exclusively in the non-AMG Mercedes lineup, and it is doing justice to the engineering work that went into the architecture.
The Driving Character That Defines the Update
Professional reviewers who drove the 2027 S-Class on winding roads and unlimited Autobahn stretches agreed on the most fundamental characteristic of the update. The ride, in all trims and drive modes, is sublime, and the overall sensation of being in your own world, isolated from the chaos outside while being propelled effortlessly, remains fully intact.
The flat-plane V8’s additional drama sits on top of this foundation rather than disrupting it. The S-Class’s fundamental character of cocooning comfort and effortless progress is uncompromised. The V8’s new character adds a layer of engagement that buyers who choose the S580 over the S500 specifically want, and it delivers that engagement without sacrificing the serenity that makes the S-Class the S-Class.
For a luxury sedan that has spent decades defining the standard that all others measure themselves against, adding genuine performance character without compromising the fundamental luxury promise is the most difficult refinement to achieve. The 2027 S580 4Matic did it with a flat-plane crankshaft, 530 horsepower, and a sound that even professional reviewers admit surprised them with its intensity.
That is not a complaint. From anyone.
