The headline here is that no longer does a thunderous eight-cylinder 63 derivative of the CLS exist. Those who crave a four-door coupé armed with such an engine will now be directed to the new four-door version of the AMG GT, while the CLS range climaxes with the straight-six 53 tested here.
Displacing just under three litres, AMG’s new 53 powerplant uses a single yet substantial conventional twin-scroll turbocharger, but it compensates for the inevitable latency of such a turbo with a smaller secondary, electrically powered ‘compressor’ mounted adjacent to the inlet ports. What results, on paper, looks like a quite spectacular spread of torque, with 384lb ft available between 1800rpm and 5800rpm, and peak power arriving reassuringly far around the tachometer, at 6100rpm.
And yet on top of that comes an extra layer of motive power supplied by an electric motor that also serves as starter-alternator for the car. Mounted between the engine and nine-speed automatic gearbox, it’s fed by a 48V system and an enlarged battery. And, as well as allowing the car to save fuel by coasting ‘engine off’ for prolonged periods and supplying the current necessary to drive that electric blower, the 48V system and drive motor combine to supplement the engine’s 429bhp and 384lb ft with up to 22bhp and 184lb ft (although, because it does most of its assisting at low crank speeds, you shouldn’t simply add two and two together and conclude this is a 568lb ft powertrain).
The car’s bodywork – less distinctive than earlier CLS generations but in no danger of being mistaken for an E-Class saloon – rests on firmer, AMG Ride Control+ air springs with adaptive dampers, and has multi-link suspension front and rear. It’s a self-levelling set-up that lowers at speed but can be manually raised for steep driveways and the like. There are three pre-sets for the suspension ranging from Comfort to Sport+, and two that alter the assistance of the electromechanical steering. Along with similar pre-sets for the engine, driveline and transmission, it should be possible to tailor the CLS 53 to any road you care to point it down.
The car has 4Matic+ four-wheel drive as standard, the torque split between the front and a permanently driven rear axle varying continuously in line with conditions under-wheel. It’s not calibrated purely with entertainment in mind, though – and, unlike with its four-wheel-driven 63 S models, AMG doesn’t include a rear-drive-only Drift mode here.