The letter ‘S’, when referenced with any Mercedes-Benz, evokes a sense of super luxury, not only amongst the select circle of automotive enthusiasts but also with the man (or woman) on the street. After all, as most would know, ‘S’ stands for Sonderklasse, or German for ‘special class’ – the top grade.

The day has finally arrived where a BEV adorns the ‘S’ badge, in the form of the EQS. We’ll take a look in detail in a feature here, but one can’t help but wonder how Mercedes-Benz’s flagship BEV stacks up against the flagship of the “old world” – the ICE-powered S-Class (albeit as a mild hybrid).

Having been no stranger to classic and modern Mercedes-Benzes alike, our two OneShift resident “uncles” took the chance to explore the S450L 4MATIC and EQS450+ to assess whether the EQS truly offers a sense of what the future of luxury automotive might be.

Hey, I know the S-Class! But what’s an EQS?

JW: The EQS represents the first ground-up developed BEV from Mercedes-EQ, while all the other EQ models share their chassis with their ICE siblings. So it’s a rather big deal. It sits at the very top of the EQ range and is a major push towards Mercedes’ aim for a carbon-neutral new car fleet within 20 years from now.

JF: As you’d expect from the flagship Mercedes-Benz, the S-Class is the trailblazer for the luxury tech which we can look forward to being trickled down in some form to the rest of the model ranges in generations to come. This W223-generation ‘S’ is locally offered in 3 specifications, starting with the 3.0-litre straight-6 powered S450L, a 4MATIC version in the middle and then the top-of-the-line 4.0-litre V8-powered S580L.

Oh, clever. Does the EQS replace the S-Class, then?

JF: Not quite, or perhaps not yet. I foresee the S-Class retaining its title as the default go-to for captains of industry, heads of state and “towkays” alike. It offers a sense of familiarity to upgraders from the W221 and W222 series.

JW: Let’s be clear, the EQS was never intended to replace the S-Class, but offers a peek into its future. Not only that, being the flagship and technological tour de force that most ‘S’ models are, it gives a flavour of the various tech that could become commonplace amongst BEVs of the future.

Does the S-Class represent a little of the old world, and the EQS the new world?

JW: You could say so. The ‘S’ clientele is getting younger, and the EQS is a very appealing car for the techy set who are less likely to be chauffeured and more keen to drive themselves. The EQS is more of a treat for the driver due to its instantaneous torque and more enthusiastic handling thanks to its lower centre of gravity. There’s more focus towards technology and using it for the driver’s benefit.

JF: Somewhat! I wouldn’t call the S450L a slouch, but at the wheel, you can feel that some build up is required for its 3.0-litre straight-6 to propel its occupants along. It is creamy smooth, and is definitely tuned for a more sedate manner of being driven, to waft you and your passengers along in maximum comfort.

As traditionally expected of the S-Class, the rear passenger-experience exceeds that of the drivers’ – the pleasure of being driven around in the plush surroundings of the hind quarters of the cabin is none other. With spades of legroom, it almost feels like being in a business class jetliner with fully reclining seats.

With all the seat and window blinds controls available at a touch of a button, coupled with fantastic sound insulation, the S-Class retains top marks as a chauffeur-driven limousine, cocoons you, and gives you a space of your own whilst on the move.

So is the EQS the more sustainable form of luxury?

JW: Its carpets are made of recycled yarn. It’s the most aerodynamic car in the world, so less energy is required for it to slice through the air. There are, of course, no tailpipe emissions. It’s probably the most sustainable way to experience an ‘S’ at the moment.

JF: It would be quite unfair to expect any petrol-powered automobile to be as green as a BEV, especially a 2 tonne, 4 wheel-drive limousine. But comparing like-for-like and considering that we almost managed to match the claimed fuel consumption figure (10.9km/ litre), the S450L is as efficient as 6-cylinder motors can get.

Being a mild hybrid, the 48V system not only manages regenerative braking and energy recuperation of the S-Class in traffic, but also assists in providing up to 22 bhp and 200 Nm of extra power on EQ mode. Combining traditional ICE-power with mild hybrid technology ensures maximum fuel savings from this M256 block.

Who should buy what?

JW: The EQS is a testament that BEVs can offer true refinement we would expect in the luxury class. As someone who primarily drives his own car, I’d pick the EQS as it just has an extra sparkle behind the wheel. That said, the sort of eerie quietness that passengers get to experience in the EQS is nothing short of spectacular. You can probably hear a pin drop.

JF: With either, you can’t really go wrong if it's the flagship, gizmo-filled model in the Mercedes-Benz lineup you’re looking for. Neither will fail in providing maximum comfort for all passengers, living up to the ‘S’ moniker.

Text by James Wong and Joel Foo; Photos by Horizon Drivers' Club