Only a few years ago, Mercedes-Benz appeared fully committed to an all-electric future, even going so far as to pledge a completely EV-only lineup before the decade’s end. Then market realities intervened. As electric vehicle demand cooled and customer preferences proved more complex than expected, the brand adjusted course. Last year, Mercedes confirmed that internal-combustion engines would remain part of its strategy for the long term—and to underline that point, it promised something bold: a brand-new V8.
That promise has now been fulfilled. This week, Mercedes unveiled its latest V8 powerplant, code-named M177 Evo, beneath the hood of a substantially refreshed S-Class sedan. While the debut itself is significant, the broader implications stretch well beyond the brand’s flagship luxury car.
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Introducing the M177 Evo V8
The new M177 Evo is a twin-turbocharged 4.0-liter V8 making its first appearance in the 2027 S-Class S580. Paired with a mild-hybrid system, the engine produces 530 horsepower and 553 lb-ft of torque, with peak torque available from just 2,500 rpm through 4,500 rpm. That wide plateau ensures effortless, linear acceleration in everyday driving conditions.
Compared with the outgoing S580, output rises significantly from 496 hp and 516 lb-ft, while Mercedes says emissions have been reduced—a notable achievement given the power increase. The hybrid assistance also improves low-speed response and overall efficiency.
A Major Evolution of a Familiar Engine
Despite its new designation, the M177 Evo is not an entirely new engine. It evolves from the M177 V8 that first appeared in AMG products in the mid-2010s. However, the updates are extensive. Engineers revised the fuel-injection system, redesigned intake and exhaust passages, and upgraded turbocharger housings and compressor wheels.
The most dramatic change lies inside the engine. Mercedes replaced the traditional cross-plane crankshaft with a flat-plane crank, a design typically reserved for high-performance sports cars. This layout reduces rotating mass and internal vibrations, allowing the engine to rev more freely and respond more quickly.
Flat-Plane Performance, Luxury-Car Refinement
Mercedes is no stranger to flat-plane crankshafts. AMG previously used one in the AMG GT Black Series, and similar setups are found in high-end performance cars from Ferrari, McLaren, and Chevrolet’s Corvette Z06 and ZR1. In the M177 Evo, the flat-plane crank works with a revised firing order to deliver sharper throttle response and higher performance potential.
Flat-plane engines are known for their higher-pitched exhaust note, but because this V8 debuts in a luxury sedan, Mercedes added additional sound insulation to maintain the S-Class’s trademark quiet cabin.
The integrated mild-hybrid system further enhances refinement, providing torque assistance at low speeds, enabling regenerative braking, and allowing seamless engine restarts—all while contributing to improved fuel efficiency.
What This Means for AMG’s Future
Beyond the S-Class, the new V8 has major implications for Mercedes-AMG. AMG is developing its own flat-plane-crank V8, though it remains unclear whether that engine will be a direct derivative of the M177 Evo or a separate evolution of AMG’s M178 engine currently used in the GT lineup.
Patent filings uncovered last year suggest AMG is even experimenting with ways to retain its signature deep exhaust burble something flat-plane engines typically lack—hinting at innovative acoustic solutions.
The first AMG application of the new V8 is expected to arrive in a CLE 63 model developed under Mercedes’ low-volume Mythos program, with camouflaged prototypes already spotted testing. An even more extreme CLE variant is also rumored, joining the exclusive Mythos lineup alongside models like the Purespeed speedster. The upcoming AMG GT Track Sport is also expected to use a version of this engine.
Not all AMG fans will be thrilled, however. Reports suggest future versions of the C63 may continue with an inline-six configuration rather than returning to V8 power.
A Clear Signal From Mercedes
The debut of the M177 Evo sends a clear message: Mercedes is no longer betting exclusively on electrification. Instead, the brand is embracing a diversified strategy that balances EVs, hybrids, and high-performance combustion engines. For enthusiasts, the return—and evolution—of a modern V8 confirms that the internal-combustion engine still has a meaningful role to play in Mercedes’ future.