2021 Mercedes-Benz S-Class safety tech: Rear-seat airbags and 48-volt architecture

The new S-Class comes standard with a whole bunch of new driver-assistance features.

Steven Ewing Former managing editor
Steven Ewing spent his childhood reading car magazines, making his career as an automotive journalist an absolute dream job. After getting his foot in the door at Automobile while he was still a teenager, Ewing found homes on the mastheads at Winding Road magazine, Autoblog and Motor1.com before joining the CNET team in 2018. He has also served on the World Car Awards jury. Ewing grew up ingrained in the car culture of Detroit -- the Motor City -- before eventually moving to Los Angeles. In his free time, Ewing loves to cook, binge trash TV and play the drums.
Steven Ewing
3 min read
2021 Mercedes-Benz S-Class
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2021 Mercedes-Benz S-Class

The new S-Class will debut later this year.


As Mercedes-Benz's flagship, the arrival of a new always means the introduction of some fancy new features that'll slowly trickle down to the rest of the company's lineup. We've already told you about the updated MBUX infotainment tech coming to the 2021 S-Class, but Mercedes-Benz detailed a number of other features during its debut Wednesday, including the first example of a rear-seat airbag in a production car.

Available with the S-Class Executive Line, these airbags deploy out of the backs of the front chairs. Mercedes says compressed gas inflates "a wing-shaped structure," at which point "a large, tent-like airbag deploys between the two wings." The specific tubular structure of the rear-seat airbags is very different from what you find up front, and Mercedes says this means this means they can inflate with "comparatively low force and a low risk of injury," compared to traditional airbags.

The rear-seat airbags work in conjunction with the S-Class' inflatable seatbelt -- a bit of safety tech that's already found on a number of production cars. Speaking of seatbelts, Mercedes says the S-Class will be available with "illuminated designer belt buckles," making them easier to locate and fasten in the dark. They look fancy as hell, too.

2021 Mercedes-Benz S-Class
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2021 Mercedes-Benz S-Class

The S-Class' body can automatically raise itself up to 3 inches in the event of a side-impact collision, just in case a rogue inflatable Prius ever catches you off guard.


48-volt architecture

The S-Class will be the latest Mercedes-Benz to get 48-volt chassis tech, which opens the door for a number of functions. The S-Class gets the same (optional) E-Active Body Control system as the GLE-Class and GLS-Class SUVs, smoothing out road imperfections and counteracting body roll. Mercedes' Curve driving mode will be on hand, too, where the car actively leans into bends, which can help quell motion sickness.

For the S-Class, the 48-volt architecture unlocks Road Surface Scan, which uses stereo multipurpose cameras to read the road ahead of the car and adjust the suspension accordingly. Theoretically, this should make for a super smooth ride, even over rough pavement.

Finally, the 48-volt system allows for the implementation of Mercedes' Pre-Safe Plus Impulse Side tech. If the car detects an impending side collision, the S-Class can automatically raise itself up to 3 inches, which reduces the load on the door structures. Mercedes-Benz isn't the first company to offer this kind of safety tech on a luxury sedan, though -- in fact, rival introduced this on the A8 a few years ago. Interestingly, Mercedes-Benz says this feature won't be available right at launch, but will come online shortly thereafter.

2021 Mercedes-Benz S-Class
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2021 Mercedes-Benz S-Class

Despite its size, rear-axle steering of up to 10 degrees should make the S-Class easy to maneuver.


Rear-axle steering

The concept of rear-axle steering is nothing new, and lots of companies already offer this tech. But the 2021 S-Class will be the first Mercedes to get it, and it should prove helpful for maneuvering this long sedan. In fact, Mercedes says "the turning radius of the S-Class is reduced by up to 7 feet," which gives the car a turning circle of "less than 36 feet," which is pretty impressive for a full-size sedan. For comparison, that's a slightly smaller turning circle than Mercedes' subcompact A-Class.

What's interesting is that Mercedes-Benz will offer two levels of rear-axle steering. The Luxury Line and AMG Line cars can be fitted with 4.5 degrees of rear-wheel steering, while a second choice for the Executive Line increases that number to 10 degrees, which is greater than just about any other car currently in production. We'll be interested to test the latter setup in tight parking lots, and to see how it improves agility on winding roads.

2021 Mercedes-Benz S-Class Evolves the Flagship

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Driver-assistance features standard

Every 2021 S-Class will come with a 360-degree camera standard, which aids with automatic emergency braking, parking assist and more. The Active Parking Assist function gets a few improvements, largely thanks to the increased number of exterior cameras and sensors, as well as the integration of rear-axle steering.

We already detailed many of the S-Class' other new features, including the active blind-spot assistance that can actually sense when you're going to open the door, and warn you in advance if there's a pedestrian or another vehicle approaching.

But the best thing about the 2021 S-Class? The full suite of driver-assistance tech -- save the E-Active Body Control and rear-seat airbag -- will come standard across the board. Yes, many luxury automakers still charge for these niceties, but Mercedes-Benz is equipping them on every US-spec S-Class. Safety first, after all.

Watch this: 2021 Mercedes-Benz S-Class: Our first look at new luxury

Originally published July 29.