Car Enthusiast - click here to access the home page


First UK Drive: Mercedes-Benz CLS 400 d. Image by Mercedes-Benz.

First UK Drive: Mercedes-Benz CLS 400 d
The third-generation Mercedes CLS is a hugely convincing package with this mighty 400-badged diesel engine.


<< earlier review     later review >>

Reviews homepage -> Mercedes-Benz reviews

Mercedes-Benz CLS 400 d

4 4 4 4 4

In an increasingly packed Mercedes-Benz product line-up, you might think there was no longer a need for the third-generation CLS. But when you drive one with this particularly potent straight-six diesel, you'll wonder why you'd want anything else.

Test Car Specifications

Model tested: Mercedes-Benz CLS 400 d 4Matic AMG Line
Pricing: CLS range from 51,870; 400 d 4Matic AMG Line from 60,740, car as tested 70,065
Engine: 2.9-litre straight-six turbodiesel
Transmission: 4Matic all-wheel drive, 9G-Tronic nine-speed automatic
Body style: four-door 'coupe'
CO2 emissions: 156g/km (VED band 151-170: 515 first 12 months, then 450 per annum years two-six of ownership, then 140 annually thereafter)
Combined economy: 47.9mpg
Top speed: 155mph (limited)
0-62mph: 5.0 seconds
Power: 340hp at 4,400rpm
Torque: 700Nm at 1,200-3,200rpm
Boot space: 520 litres

What's this?

The Mercedes CLS, this time with '400 d' badging, which means it packs a whopping 340hp/700Nm turbodiesel mill. It's the same 2.9-litre, straight-six engine as we tried in the CLS 350 d at launch, only here it's blessed with an additional 54hp and 100Nm, for those aforementioned, rudely healthy peak outputs. That brawn is enough to allow this black-pump CLS to run a five-second-dead 0-62mph sprint, all while returning quoted economy and CO2 emissions figures that are just 2.5mpg and 8g/km shy of what the 350 d can purportedly attain. Otherwise, it's 'as you were' with the Mk3 CLS - the looks are perhaps not quite as elegant and distinctive as its two predecessors' aesthetics were, but it's still a very handsome car that's clearly not just an E-Class in a fancy frock and the interior is simply exquisite; the quality of the fixtures and fittings, the dramatic visuals of the fascia, the way the twin 12.3-inch TFT screens operate, the comfort levels within - it's all superb in here. Even if rear-seat space is just a teensy bit cosier here than it might be in other M-B products at the same price point...

How does it drive?

Brilliantly, in much the same way the 350 d does. Only now, you have just a bit more firepower to play with. It's actually quite noticeable, the 400 d really surging forward in a feisty and eager fashion, on both part-throttle and more meaningful 'stepping-upon' applications of what some people refer to as 'the gas'. No matter how you're summoning up the 400 d's thump, it merely reinforces the fact this is one seriously quick car, irrespective of what fuel-stuff is propelling it down the road. The inline-six loses none of its unflappable composure by being turned up to 340hp, either, because at most you'll hear a pleasing aggressive snarl from it - like an old straight-six petrol from some other German car company we could mention, but won't out of courtesy to Stuttgart - and for the rest of the time, it's almost totally inaudible. Add in the ultra-fluid 9G-Tronic gearbox and the instant, tractive shove of 4Matic and this is one of those modern performance cars that has you thinking 'ten years ago, I'd have accepted this as being the ultimate incarnation of a full-blooded AMG'.

Having said that, it's not incredibly engaging in the corners, mind, although - for a big four-door 'coupe' - it remains extremely well-sorted. The steering is great, which seems to be a Mercedes (and, by extension, Mercedes-AMG) strength these days, but it still doesn't offer the final word in granular feel. The ride quality is magnificent, no problem there, but in Sport and Sport+ modes, the Air Body Control suspension (part of a 2,495 Comfort Package on our test car) just firms things up a little too much for cruddy British back roads being traversed by 19-inch wheels. Thus, you keep the car in Comfort and that means the mass of the CLS (a meaningful 1,935kg, in this particular trim) isn't quite as perfectly controlled as you might like when the curves arrive. Also, as Neil said at launch, you probably don't need the 400 d; as lovely as this 340hp model is, the 350 d does 99.9 per cent of the same stuff for less money.

But these are minor observations. Truth is, the CLS 400 d feels a much finer, dynamically rewarding car than one of its key rivals, the Audi A7 Sportback, and you also feel that BMW's forthcoming 8 Series Gran Coupe is going to have its work seriously cut out for it, if it fancies toppling the CLS.


While there's a financial argument to be made for opting for the CLS 350 d instead, it's nice to know vehicles like the powerhouse CLS 400 d exist. Classy, composed and yet quite indecently quick when the mood takes you, this is a graceful and economical big four-door executive car that provides an interesting alternative to the more traditional 'norm' in this segment.

4 4 4 4 4 Exterior Design

5 5 5 5 5 Interior Ambience

4 4 4 4 4 Passenger Space

4.5 4.5 4.5 4.5 4.5 Luggage Space

4.5 4.5 4.5 4.5 4.5 Safety

4.5 4.5 4.5 4.5 4.5 Comfort

4 4 4 4 4 Driving Dynamics

5 5 5 5 5 Powertrain

Matt Robinson - 17 Dec 2018    - Mercedes-Benz road tests
- Mercedes-Benz news
- CLS images

2018 Mercedes-Benz CLS 400 d. Image by Mercedes-Benz.2018 Mercedes-Benz CLS 400 d. Image by Mercedes-Benz.2018 Mercedes-Benz CLS 400 d. Image by Mercedes-Benz.2018 Mercedes-Benz CLS 400 d. Image by Mercedes-Benz.2018 Mercedes-Benz CLS 400 d. Image by Mercedes-Benz.

2018 Mercedes-Benz CLS 400 d. Image by Mercedes-Benz.2018 Mercedes-Benz CLS 400 d. Image by Mercedes-Benz.2018 Mercedes-Benz CLS 400 d. Image by Mercedes-Benz.2018 Mercedes-Benz CLS 400 d. Image by Mercedes-Benz.2018 Mercedes-Benz CLS 400 d. Image by Mercedes-Benz.


Internal links:   | Home | Privacy | Contact us | Archives | Old motor show reports | Follow Car Enthusiast on Twitter | Copyright 1999-2023 ©