Parkers overall rating: 4.1 out of 5 4.1
  • Broad spread of engine talents with petrol, diesel and mild-hybrid
  • Entry-level motors plus 3.0-litre inline sixes at launch
  • AMG performance model offers the best of both worlds

What engine options are there?

The CLS is available with three engine choices: two diesels – including the most powerful Mercedes-Benz has ever produced – plus a solitary petrol. One is a 2.0-litre four cylinder, the other two displace 3.0 litres and have six cylinders. All come with 4Matic all-wheel drive and a nine-speed automatic gearbox as standard.

Petrol engine

Engine Power and torque
0-62mph time
Top speed
CLS 53 AMG 4Matic+ 435hp, 520Nm 4.5secs 155mph

View full specs

Top of the tree in terms of performance is the Mercedes-AMG CLS 53 4Matic+ – a standalone performance model, like those badged 43 within the C and E Class ranges, that act as an entry point to a full fat, V8 AMG model. Only there isn’t one of those in the CLS range.

This uses the a 3.0-litre petrol inline six-cylinder plus EQ Boost motor (below). Mercedes-Benz says that this is the most sophisticated engine it has ever made. Power is 435hp at 6,100rpm and 520Nm of torque from 1,800-5,800rpm.

It’s a mild hybrid that features an EQ Boost starter-alternator for a temporary lift of 22hp and 250Nm of torque, and 48-volt electrical system powering things like the water pump and air-conditioning. The first thing that strikes you is how much performance there is at low revs. There’s bags of throttle response, and plenty of thrust at high revs, with a charismatic, but muted, bellow to accompany it. Although it’s not as soulful as the older 43-badged V6.

Diesel engines

Engine Power and torque
0-62mph time
Top speed
CLS 300 d 4Matic 265hp, 550Nm 6.4secs 155mph
CLS 400 d 4Matic 330hp, 700Nm 5.2secs 132mph

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The smallest diesel unit is badged CLS 300 d 4Matic and is a 2.0-litre, four-cylinder motor. Like the rest of the range it comes with a nine-speed automatic transmission, and for 2021, it gains an additional 20hp. It’s a quiet cruiser and accelerates quickly, gaining momentum effortlessly and effectively. It doesn’t really sound like a four-cylinder engine at all, although it can get vocal if you’re pushing hard.

Moving up to the 400 d 4Matic, and the performance ramps up consideraby. We’ve yet to drive the facelifted version, but the older model is nearly identical in terms of power and torque. It’s the most powerful series production diesel engine Mercedes-Benz has ever produced – the 0-62mph dash takes just 5.2 seconds which puts it among some very quick cars.

To put it bluntly it’s an absolute sledgehammer of an engine with effortless acceleration from very low revs and a deep well of power held in reserve. It’s near silent while cruising and develops a menacing grumble when pushed. As such, it suits the CLS handsomely.

All variants of the new CLS feature Mercedes-Benz’s fast-shifting 9G-Tronic automatic gearbox, upgraded to an AMG Speedshift in the CLS 53. This promises imperceptible changes for comfortable cruising, or rapid-fire shifts when pressing on. A choice of modes from the Dynamic Select menu gives you a choice of Eco, Comfort, Sport, Sport Plus and Manual shifting behaviours ranging from languid to hasty.

The CLS 53 4Matic+ uses an AMG-tweaked Speedshift version of this ‘box, with faster paddle responses and double declutching function for multiple downshifts, so you can rapidly decelerate before a corner and ensure you’re in the correct gear for the exit.

Handling

  • Standard springs, adaptive dampers and air suspension options
  • Body control is impressive with excellent agility
  • 4Matic all-wheel drive produces ample grip

The CLS is a smooth, refined cruiser but that doesn’t means it’s not keen in the corners. It uses a clever front suspension system with lots of lightweight aluminium components to help enhance front-end agility.

As a result the coupe responds quickly to steering inputs and turns into corners with confidence – aided by well-weighted steering that varies its ratio in response to steering angle. The steering feels slow around the straight-ahead position and faster when wound all the way round.

There’s a lot of car here and as such bodyroll is inevitable. Happily it all well controlled – the suspension and anti-roll bars stabilize the car quickly – so you don’t need to let the CLS settle for long before changing direction again. Standard-fit Dynamic Select allows you to tailor the car’s responses and control weights, with increasingly performance-orientated Comfort, Sport and Sport+ modes on offer.

CLS AMG 53 4Matic+ handling

The sporting petrol CLS features much of the same tech as the standard car but with everything amplified for maximum driver enjoyment. Four-wheel drive (called 4Matic+) works faster to deliver traction where it’s needed most, while air suspension is fitted as standard with a specific AMG tune.

Adaptive dampers firm up the spring rate when cornering and braking to reduce body movements and geometry tweaks including more negative camber on the front axle improve cornering grip. The steering’s a real highlight, an AMG hallmark, with a nicely judged weighting and level of feedback, plus in the car we drove, an alcantara wheel to hold onto.

The AMG CLS still feels like a big car but it’s noticeably sharper in all dimensions than the standard CLS, and stakes its claim as a fully-fledged performance saloon.