Mercedes-Benz S 450 (2021) review
An all-new Mercedes S-Class charges ahead in the fight for luxury car supremacy.
Michael Taylor

Published on October 27, 2020

Mercedes-Benz has been doing S-Classes for a long time now, and it has rarely done them poorly, so there's pressure on the latest S-Class, due in 2021, to set new standards of luxury. It's safer than it has ever been, more luxurious, more technologically advanced, more user friendly, more intuitive and faster than ever. Is it the finest luxury car you can buy in the sector today?

In the metal

There has been a welcome throwback in the new S-Class's design to a time when the flagship Mercedes-Benz carried a clean design that didn't age through its flashy details. It's an awfully big car, though it hides it well. It's 34mm longer, 55mm wider and 12mm higher than the outgoing S-Class. It's just big. But it's also nicely proportioned and looks light on its feet.

The seats can be optioned up to carry 19 motors each, ranging from longitudinal, height, angle, backrest and head restraint adjustment to seat cushion depth and even (for the front passenger) heel support adjustment.

There can be four vibration motors to massage each body in each seat, five fan motors, a motor for the lumbar support and another one for the adjustable side bolsters.

The instrument cluster has been upgraded with the option of three-dimensional displays, and augmented reality has found its way into the head-up display.

It's just absurdly comfortable and complicated without ever feeling complex.

The luggage area is a practical 550 litres (30 more than the outgoing car holds), and the interior is, well, everything Mercedes-Benz can currently manage in luxury and technology. And Mercedes-Benz can currently manage quite a lot, it seems. Take a scroll through the gallery to get a flavour for it.

Driving it

We drove four versions of the new S-Class, the S 450 feature here, the S 500, the S 580 and the plug-in hybrid S 580 e. No diesels were available at the launch event, though they're expected to remain the best-sellers in Ireland for now. The entry-level petrol car, the S 450, is hugely impressive, the mid-range S 500 is needlessly quicker and the S 580 is simply a divine piece of engineering.

All three regular petrol models run an integrated starter generator (ISG), which uses a 48-volt 'mild hybrid' electric system to maximise brake energy regeneration and boosting performance. It's not zero emissions, but it's not nothing and it allows Benz to use smaller combustion engines than it might have.

The S 450 is powered by a 367hp/500Nm version of Benz's 3.0-litre, in-line six-cylinder engine, which is mated to the ISG at the front and a nine-speed automatic gearbox at the back. It's the only petrol S-Class available with rear-wheel drive, incidentally.
It's quicker than it has any right to be, too, ripping to 100km/h in 5.1 seconds on its way to a limited top speed of 250km/h. The S 500 is more of the same, using the same core powertrain, but boosted to 435hp and 520Nm, and it slips under the five-second barrier to record 4.9 seconds to 100km/h.

Then there's the big boy, complete with a 503hp, 700Nm 4.0-litre V8 developed by AMG, and mated to a second-generation ISG, worth 15kW (20hp) and 180Nm of torque. There are no official performance figures on the S 580 at the time of writing, but it feels like a low four-second car to 100km/h.

The gorgeousness of the S 580 isn't its excess power and speed, though it has clearly more than enough of both. It's so smooth, luxuriant, indulgent and sophisticated that it just feels entirely in keeping with the rest of the S-Class's engineering. It's an incredibly quiet engine. Sure, push it on and you can hear its melodic sound, but it's never anything other than quiet.

The chassis continues the masterclass. The adaptive air suspension system irons out every road imperfection up to 60km/h, then does its best to steamroll the rest. It can lean in to corners, like a motorbike, leading to cornering speeds that are downright ludicrous in a car like this, and it is all an incredibly unflustered experience.

Then there's the rear end, where the new rear-wheel-steering option delivers 10 degrees of turn, slashing two metres from the turning circle, but also adds a whole new level of agility and stability to road driving.

There is nothing the S 580 does poorly (other than using an oddly squishy, two-step brake pedal arc), though the transmission can sometimes catch itself out for the occasional jerking downshift when it's being driven quickly.

The S 450 is, oddly, less convincing, and the S 500 is in the same boat. The straight-six petrol engines, so wonderful in other Benzes, feel coarser and harsher here, especially in their exhaust notes.

The rest of the S-Class seems to be an exercise in integrating disparate cutting-edge technologies that could have gone horribly wrong, but didn't.

There are at least 20 new active safety features. The rear seats can be optioned with their own front airbags. The adaptive suspension raises the body up just before any collision, to take the hit on the strongest part of the chassis. Even the seat bolstering shoves the passengers away from any collision.

It has two front radars with 130 degrees of 'vision', a long-range front radar, a pair of rear radars, a front-facing stereo camera, a 360-degree camera and 12 ultrasonic sensors.

By late next year there will be optional Level 3 driver assistance, where you just push a button and the car does the rest, but only up to 60km/h (as per an incoming EU rule).

There is even the option of Level 4 in special situations, like suitably updated carparks, where you can just leave the car and walk away while it trots off to find a space.

What you get for your money

Irish pricing for the new S-Class hasn't been determined yet so we will update this section when the information becomes available. Likewise, we don't know for sure which versions will come here. Possibilities range from the S 450 and S 500 petrol-powered in-line sixes to three diesels, from the S 350 d to the S 400 d. The brilliant V8-engined S 580 and the 100km of EV range from the plug-in hybrid S 580 e will join them midway through next year.


Mercedes is leading its S-Class assault on the luxury saloon market with cutting-edge technology and safety, while ensuring all models adopt electrification. First impressions of the petrol models suggest that, coarseness of the six-cylinder engines aside, the new S will be a formidable competitor, though perhaps in diesel or plug-in hybrid guises in this part of the world.


Tech Specs

Model testedMercedes-Benz S 450 4Matic
Engine3.0-litre inline turbocharged six-cylinder petrol with mild-hybrid assistance
Transmissionnine-speed automatic gearbox, four-wheel drive (rear-drive available)
Body stylefour-door, four- or five-seat saloon
WLTP CO2 emissions192g/km (Band F - €1,200 per annum if registered before January 1, 2021, €790 after that)
Combined economy33.6mpg (8.4 litres/100km)
Top speed250km/h
0-100km/h5.1 seconds
Boot space550 litres
Rivals to the S 450 (2021)