Mercedes-Benz doesn’t usually do mid-cycle refreshes with a flamethrower. But for 2026, the S-Class is getting exactly that—a ground-up rethink that Stuttgart is calling the most extensive update within a single generation in the model’s 50-plus-year history. That’s not marketing fluff. More than half of the car’s components have been reworked, the tech stack has been rewritten, and—because this is still a proper flagship—the V8 has been fundamentally re-engineered.
Let’s start with the headline: the S-Class is going flat-plane.
When the camouflage comes off in the coming weeks, the visual tweaks will matter less than what’s hiding under the hood of the V8 models. The outgoing M176 4.0-liter V8 gives way to a revised M177 that ditches the traditional cross-plane crankshaft in favor of a flat-plane design—the same basic philosophy used in the AMG GT Black Series. Yes, that’s a race-bred solution finding its way into a chauffeured luxury sedan, and no, Mercedes isn’t apologizing for it.
For the uninitiated, a flat-plane crank arranges its crank pins at 180 degrees rather than the 90-degree “X” layout of a cross-plane V8. The result is a lighter, freer-revving engine with evenly spaced firing pulses, a sharper throttle response, and a higher-pitched, more exotic soundtrack. Think less bassy burble, more mechanical snarl—especially as the tach needle climbs.
Crucially, this isn’t about sacrificing character in the name of emissions compliance. Quite the opposite. Output in the mild-hybrid S580 jumps from 496 horsepower to 530, trimming the 0–62-mph sprint toward the four-second mark. Engineers say the flat-plane setup actually helps reduce emissions while unlocking more performance—a rare win-win in today’s regulatory climate.
The Maybach S580 will be next in line, using a higher-output version of the same engine tuned to 603 horsepower. That motor replaces the outgoing V12, which Mercedes is quietly ushering off the European stage. It’s the end of an era, sure—but the replacement is faster, cleaner, and far more scalable across the lineup.
AMG’s updated S63 hasn’t been shown yet, but don’t expect it to sit this party out. The flat-plane M177 is also destined for other heavy hitters, including the upcoming CLE 63, signaling a broader shift in AMG’s V8 philosophy.
If V8 fireworks aren’t your thing—or your market won’t have them—the straight-six S-Class models carry on. The plug-in-hybrid S580e, in particular, gets a meaningful boost: the turbocharged inline-six rises from 362 to 443 horsepower, the electric motor increases output to 161 horsepower, and combined system power lands at a healthy 577 horses.
Inside, the changes are quieter but arguably more important. The refreshed S-Class debuts a significantly updated version of Mercedes’ MB.OS operating system, riding on what the company calls a new service-oriented electrical and electronic architecture. Translation: faster processing, more flexibility for future updates, and a digital experience that won’t feel dated five minutes after delivery.
Mercedes says the revamped S-Class is now in the final stages of road testing and close to series production. UK sales begin later this year, with pricing nudging above the current £100,000 entry point.
In a segment increasingly obsessed with electrification and autonomy buzzwords, Mercedes has taken a different tack: evolve everything, but don’t forget what makes a flagship special. A flat-plane-crank V8 in an S-Class may sound borderline unhinged—and that’s exactly why it works.
Source: Mercedes-Benz; Photos: Autocar
