Mercedes-Benz has launched its new CLS executive "4-door coupe"in South Africa in CLS 400d and fiery Mercedes-AMG CLS 53 guises. This week, we put the latter through its paces on the Kyalami Racing Circuit in Gauteng.

The Mercedes-Benz CLS is one of those interesting-looking cars that's "neither sedan nor coupe". It blends genres and, for its sins, is endowed withhead-turning looks. Boasting underpinnings from the E-Class, it's claimed to offer a balance between sportiness and luxury. At the local launch, however, Mercedes-Benz SA wanted us to focus primarily on the sportiness factor and chose to showcasethe vehicle at the Kyalami Race Circuit.

The 3rd-generationCLS' flagship derivative, the Mercedes-AMG CLS 53, is onemuscular "4-door coupe"!It adopts the new-look headlights and taillights ofits CLA sibling, which areused to differentiate the standard Mercedes-Benz sedans from their svelter coupe-likesiblings. There's also an Edition 1 package available, replete with orange copper detailing, thin striping around the wheels and some decals, plus interior tweaks.

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53 Engine?

With 320 kW and 520 Nmthe CLS 53 is a brisk performer, impressive considering its size

Okay, so 53 is a new number in the AMG family. Sitting neatly between 43 and 63, the 53 name represents a new generation of AMG powertrain. For the first time in recent history, Mercedes-Benz has gone the straight-6 cylinder route, as opposed to its much better-known V6 and V8 configurations. What's more, this new engine is supplemented by electrification. The numbers make for interesting reading:the new M256 is a 3.0-litre twin-turbocharged inline 6-cylinder motor that delivers peak outputs of 320 kW and 520 Nm.

This is where the latest advances in electrification come in. There's a starter generator located between the engine and transmission,which delivers 16 kW and 250 Nm. There is also aneBooster, an auxiliary compressor that builds up high boostbefore the large exhaust-driven turbocharger kicks in. This setup has effectively eliminated turbo lag and provides a particularly esponsive engine, which is very eager in the appropriate driving modes.

The performance claims are credible:0-100 kph is said to take4.5 seconds and it'll run to a limited top speed of 250 kph. Tick the Driver's Package and you'll reach 270 kph.Mated with this new engine is a 9-speed twin-clutch transmission, in combinationwith a 4Matic+ all-wheel-drive setup.

Ride and drive

Our ride and drive experience afforded usa chance to evaluate the CLS 53's straight-line grunt and dynamicprowess on track.The Dynamic Select drive programmes allow you to effortlessly switch between the Comfort day-to-day modeand the more performance-biased Sport and Sport+. We went straight to the latter, for obvious reasons. Does the CLS 53 deliver in the performance stakes, despite it not being a V8-powered 63?

Oh yes – and how! The new i6 engine delivers a soulful and deep roar upon full acceleration, interrupted only by the software-induced gearshift bangs. It sounds meaty right from the get-go too, and never seems to lose its urgency even when the motor is rapidly approachingitsred line.

Make the best of that active exhaust and enjoy the glorious soundtrack!The electric motor and petrol enginework well together; it's virtually impossible to feel the interactionbetween the two. Once the revs climbsufficiently and the exhaust turbocharger comeson song, the electric-effect dissipates.It's remarkably smooth– the interchange is so seamless, which is incredible when you consider how much is going on in the powertrain.

Incredibly, the Mercedes-AMGCLS53 is capable of hitting 100 kph from a standstill in under 5 seconds, despite no launch control or Race mode. It's not pull-your-face-off quick, which is to be expected given the vehicle's dimensions and weight, but despite this, it's deceptively lithe when it carves up corners. We had the chance to fling the vehicle around the Kyalami circuit, which is notorious for its elevation changes and fast corners.

The rear of the Mercedes-AMG CLS 53. Note the quad exhaust setup.

For a car tipping the scales at a touch under 2 tonnes (its official kerb weight is 1 980 kg), cornering prowess is surprisingly good. We think the secret here is the new 4Matic+ all-wheel-drive system, which, in conjunction with a well-sorted chassis, instils a sure-footed feeling. The CLS 53is primarily driven by itsrear wheels, with the front axle coming into play when a loss of traction is detected.Granted, the laws of physics still apply and the brakes needed to be cooled after some spirited laps. The steering is worth a mention too:it's particularly direct and there's generous feedback.

Sadly we had no chance to drive the vehicle on a public road. The racetrack surface is naturally exceptionally smooth with hardly any bumps, so an accurate assessment of the newcomer's ride quality will have to wait until we get the vehicle on test.

Mercedes-Benz CLS prices in South Africa (May2019)

CLS 400d 4Matic – R1 194834

Mercedes-AMG CLS 53 4Matic+ – R1 502 100

Mercedes-AMG CLS 53 Edition 1 4Matic+ – R1 706 900

Summary

The cabin of the Mercedes-AMG CLS 53 is a spectacular place to be thanks to extensive use of carbon fibre and leather.

While the overwhelming majority of AMG adoration is reserved for 63-badged models, there will be (and should be) more than enoughlove for these "AMG lite" versions. Incomparison with its 4.0-litre V8-engined siblings, the CLS 53 offers 90% of the performance with the bonus of a bit more on-road comfort. While we didn't have a chance to drive it on a public road, we suspect that the newcomerwill offer a sedate,refined ride quality.

Inside, it boasts all the latest luxury appointments and convenience features. The extended infotainment screen, which stretches across almost the entire width of the dashboard, is optionaland, to be perfectlyhonest,it really suits the car. The AMG also adopts the latest iteration of Mercedes-Benz sports steering wheel (adorned with tiny touchpads) and there are the aesthetically pleasing turbine-style climate control vents on the fascia.

It appears that there won't be a V8-powered CLS any time soon, but given the performance of the new 53 engine and our past experience with the previous generation CLS 63 S, we think this package is a lot more manageable – it certainly offers a superior blend of performance and luxury.

Further reading:

Mercedes-AMG CLS 53 (2018) Launch Review

All-New Mercedes-Benz CLS Breaks Cover

Mercedes-Benz CLS 63 AMG S (2014) Review

Drag Race: Mercedes A45 AMG vs CLS 63 AMG S