The World’s Definitive Luxury Sedan Will Get a V8 Typically Meant for Supercars

The Mercedes-Benz S-Class is gearing up for one of its biggest mid-cycle refreshes ever. But in addition to the usual suite of exterior and interior design updates, equipment upgrades, and more, it’s also getting a completely-new V8.

However, it’s not just any V8. Rather, according to various sources, who attended a recent media event and got a chance to sample the new S, the new V8 will feature a flat-plane crankshaft.

This is a huge development as it’s very unconventional for a humdrum luxury sedan to utilize a flat-plane crank engine. It also means the new V8-powered S-Class will be even more of a performance machine, especially for a non-AMG model.

A true motorsports-bred V8

Mercedes-Benz

For those unfamiliar, a flat-plane crankshaft is an internal combustion engine component design often reserved for ultra-high-performance applications. Such applications include supercars, like Ferrari, McLaren and Lamborghini, and purebred racecars.

A flat-plane crank means its crank pins are arranged in a 180-degree alternating pattern, directly opposite each other. Nearly all other internal combustion engines typically utilize a more conventional cross-plane crankshaft design.

The pins on a cross-plane crankshaft are typically angled at 90 degrees from each other.

Because flat-plane crankshafts directly offset each of the cylinder’s throw pins (where the connecting rods connect to the crankshaft), there’s less metal in the shaft assembly. The result is less rotational mass, which translates to exponentially quicker throttle responses, faster revolution speeds, and even more power.

Mercedes-Benz

Those attributes are why most racecars and high-dollar supercars use engines with flat-plane cranks.

However, because flat-plane crankshafts have less rotational mass to cancel out each cylinder’s opposing forces, they often produce more vibrations and are less refined. Which is the opposite of what engineers and designers want in the application of a full-size luxury sedan.

But despite its flaws, compared to cross-plane cranks, AutoCar reports the new V8 doesn’t compromise much in the way of refinement.

“The most extensive update in one generation”

Mercedes-Benz

Mercedes-Benz executives previously teased the extent of the W223 S-Class’s midlife refresh in conferences over the past couple of years. With the W223 nearing six years old, it’s well overdue for an update at the very least.

Mercedes-Benz

According to AutoCar, who spoke with Mercedes-Benz engineers, more than half of the W223’s components underwent a redesign or significant reengineering process. That fun-fact also apparently makes the W223’s update “the most ambitious product launch program in Mercedes-Benz history.”

Mercedes-Benz

The biggest highlight of the update, however, is the new V8. Internally dubbed the “M177,” the new eight-cylinder replaces the S 580’s current “M176.”

Mercedes-Benz

The M177 still displaces 4.0-liters with two turbochargers. But with the new crankshaft design and other updates, more power is on tap.

Compared to the S 580’s current 496-horsepower output, the new M177 supposedly punches out 530. However, the other highlight is considerably less emissions, which was one of the primary goals of the new engine.

With all said and done, the new updated W223 S-Class will debut later this year with sales launching shortly thereafter.

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