Mercedes-AMG has just extended its model range by introducing a new model designation called the 53-series, offered on the CLS, E-Class Coupé and E-Class Cabriolet models, in conjunction with the ongoing 2018 Detroit Autoshow.
The 53-series sits between the ‘entry-level’ (3.0-litre twin-turbo) AMG 43-series that delivers 367 hp/520 Nm and the (4.0-litre twin-turbo V8) 63-series, which outputs 571 hp/750 Nm as standard, and 612 hp/850Nm in ‘S’ trim.
At the heart of the 53-series is the (M256) 3.0-litre turbocharged and direct-injected power plant from a new family of inline-six petrol engines, that have been developed for electrification from the outset.
The newly developed 3.0-litre inline six-cylinder engine is supplemented by a single-turbocharger and auxiliary electric-driven compressor. The powerplant generates 435 hp and delivers a maximum torque of 520 Nm (in all three models).
The engine is aided by an ‘EQ Boost’ starter-alternator which is able to momentarily provide an additional 16 kW (21 hp) and 250 Nm of torque depending on driving conditions. The EQ Boost starter-alternator (ISG) combines a starter motor and alternator in a powerful electric motor which is fitted between the engine and transmission.
Supported by the EQ Boost starter-alternator when moving off, the electric auxiliary compressor (eZV) builds up a high charge pressure without any delay, for a faster increase in torque for acceleration until the large exhaust gas turbocharger is deployed. As a result, the 3.0-litre engine provides instantaneous throttle response with limited or no turbo lag.
Enabling the ISG system is a 48 V onboard electrical system. Power for the 48 V electrical system is generated by the EQ Boost starter-alternator. The conventional 12 V network is likewise supplied from the new network – using a DC/DC converter, to power the lights, cockpit, infotainment, and control units.
Thanks to the 48 V battery, the overall battery capacity in the vehicle is increased, enabling more electrical energy to be made available and allows new vehicles functions to be introduced, such as powering the water pump and air-conditioning compressor and dispenses with the need for a belt drive for these components.
The omission of drive belts thus allows a more compact design for the inline-six engine and creates space for an exhaust gas after-treatment system mounted closer to the engine, thereby increasing efficiency.
The 48 V onboard electrical system also paves the way for further hybridisation.
The engine is coupled with the AMG Speedshift TCT 9G 9-speed automatic transmission which features a double-declutching function and can perform multiple downshifts.
Power is transferred to the road (in all models) by the AMG Performance 4Matic + all-wheel drive system. The intelligent allows fully variable torque distribution between the front and rear axle (seamlessly transitioning from rear-wheel to all-wheel drive) and vice versa thanks to electro-mechanically controlled clutch that connects to the permanently driven rear axle and variably to the front axle.
The best possible torque split is continuously computed and deployed based on a complex matrix, courtesy of intelligent control systems that were developed into the overall vehicle system architecture.
In terms of performance, the CLS 53 and E53 Cabriolet accelerates from zero to 100 km/h in just 4.5 seconds and achieves an electronically-governed top speed of 250 km/h (270 km/h with the Driver's package). The Coupe completes the century sprint a touch faster at 4.4 seconds.
Combined fuel economy is rated at 8.4-litres/ 100km for the CLS 53 and E53 Coupe models respectively, the E53 Cabriolet manages 8.5-litres/100km.
The 53-series is fitted as standard with AMG Ride Control+ air suspension, which features a sporty spring and damper set-up, and continuously ADS+ adjustable damping system. The front axle is fitted with special steering knuckles and load-bearing joints; all components have been optimised in terms of rigidity. A greater negative camber on the front axle and on the multi-link rear axle enhances lateral dynamics.
Thanks to pneumatic all-round self-levelling, the 53-series models maintain a constant ride height regardless of the vehicle load and is able to increase the vehicle ground clearance at the press of a button. The ride height level is automatically lowered when driving at higher speeds.
An electromechanical speed-sensitive steering features a variable ratio in the 53-series models whereby steering power assistance is available in a choice of two modes – "Comfort" or "Sport".
Perforated and internally ventilated (370 mm) brake discs with 4-piston fixed callipers are fitted at the front, with internally ventilated discs measuring 360 mm and single-piston floating callipers at the rear.
As for driving assistance – the CLS integrates technology from the S-Class flagship. Fitted as standard are Active Braking Assist, Lane Keeping Assist, Attention Assist, Speed Limit Assist and the occupant protection system Pre-Safe. Also part of the standard specification is Pre-Safe Sound which prepares human hearing for the anticipated accident noise when there is a risk of a collision.
Visually, the new 53-series models have a distinctive twin-blade radiator grille in silver chrome, previously reserved only for the V8 performance models, in place diamond radiator grille with individual pins. The grille in front of the central radiator now features a black lattice pattern.
The front apron (A-wing) is equipped with black flics and a front splitter in silver chrome. The outer air intakes have two horizontal fins in silver chrome. Round the flanks AMG-specific side sill panels lend the 53-series models a more dynamic silhouette.
At the back – the 53s feature a redesigned rear apron and the classic round twin tailpipe trim elements in high-gloss chrome. The sides of the mud flaps are designed to improve air flow around the wheel arches. Lastly, the spoiler lip on the boot lid is painted in the body colour, but is optionally also available in carbon fibre.
Additional features of the CLS 53 include additional side air curtains to direct airflow to improve improving the aerodynamics at the front and reducing the car’s Cd figure. The front splitter connects seamlessly with the air curtain and reduces lift at the front axle. The outer lines of the radiator grille widen towards the bottom and lend the CLS an aggressive appearance. The CLS 53 is equipped with 19-inch light-alloy wheels as standard, optional 20-inch wheels are also offered.
As for the infotainment system, there isn’t much difference from the rest of the CLS and E-Class range – with two 12.3-inch displays under one shared screen making up the Widescreen cockpit. The AMG menu, on the other hand, displays the engine and transmission oil temperature, lateral and longitudinal acceleration, engine output and torque, boost (charge pressure), tyre temperatures and pressures as well as the current vehicle set-up.
In the case of the E-Class Coupe and Cabriolet model, the seats are trimmed in AMG-specific seat upholstery layout with an AMG badge, red seat belts plus trim elements in carbon fibre or glass fibre in matt silver. The interior is rounded off with the new, standard-fit AMG Performance steering wheel in Nappa leather with additional individualisation options such as wood inserts or Dinamica microfibre in the grip area.
With regard to interior colours and materials, the three new 53-series models boast significantly more options than the preceding 43-series models – there is a choice of Artico man-made leather/Dinamica microfibre, Nappa leather, and Designo interiors.
For the CLS 53 alongside the Designo appointments, customers have a wider choice of trim colour combinations in which the ambient colour is also repeated on the steering wheel rim. In the CLS 53, the integral seats with adjustable head restraints have also been redesigned and enhanced in terms of their shape, colour and material choice. The rear seat row has also been redesigned with three full-size seats. The seat backrest which folds in a 40:20:40 split also includes height-adjustable head restraints for increased practicality.
Limited run ‘Edition 1’ models of the CLS 53 4MATIC+ boast the Copper Art interior design – numerous highlights in a copper colour help ensure a luxurious cabin space. The leather upholstery in black Nappa also features copper-coloured contrasting topstitching, as do the instrument panel, armrests, centre console, door panels and piping on the floor mats.
Further Edition 1 niceties include centre console in carbon fibre with Copper Art copper stitching, steering wheel with Edition badge, ambient lighting with 64 colours, the Memory and Mirror package, and the exclusive IWC analogue clock.