AMG’s new straight six a tech jewel

Mercedes-AMG’s local launch of its latest Performance 53 power unit last week is a significant one. Its arrival in the new E Coupe and Convertible and the slick new CLS we have already touched on, not only moves the middling performance race on to a new level versus the likes of Stuttgart’s traditional Bavarian Propeller & Rings rivals, but it also now adds hybridisation in a most sensible manner.

This all-new 320kW 520Nm 3-litre straight six with double forced induction via the combination of a traditional exhaust-driven turbocharger and an electrically driven auxiliary compressor, all working in tandem with a 48-volt EQ Boost collar hybrid starter generator not only boosts performance, but it further improves economy too. 

Turning a quick and slick AMG Speedshift TCT 9-speed automatic and 4matic AWD, it returns 0-100km/h in the 4.5 seconds mark depending on the chassis to which it is applied and provides the expected 250km/h top whack, although you can have 270km/h if you tick that Driver’s Package box. For now, 53 is available in the three models noted and will likely spread to most other Merc models that currently employ the old V6 43 set-up. 

I call it a power unit for good reason — like this engine’s distant F1 cousin, 53 uses various aspects to do its job — and to damn good effect too, if first impressions are anything to go by. It’s also quite intriguing that Benz has opted to return to a straight-six some twenty years after moving away from that configuration for a V6, but how the car uses its EQ Boost hybrid is perhaps the most interesting of the lot. 

The EQ Boost collar hybrid — in other words, a powerful two-way 48-volt starter generator and alternator (running in tandem with a good old conventional 12V system to power the regular ancillaries) and which sits between the engine and the transmission, temporarily delivers a 16kW 250Nm bonus boost from idle until the other bits are all wound up for a truly lag free driving solution. Or intelligent electrification, as AMG likes to call it. 

The collar furthermore works as a stop-go system and even backs up the engine’s idling where necessary, to reduce standing traffic fuel wastage. Getting back to the engine, the electric auxiliary compressor or e-turbocharger produces boost without delay — in essence creating a neat electric anti-lag solution that produces the same results as a rally car’s wild and quite destructive pop-pop-bang that fires into the exhaust on deceleration to keep the turbo spooling. The AMG device uses battery power...

So, the e-turbocharger takes care of the split second that the larger exhaust-driven turbocharger needs to spool up and kick in, the two compressors working together to provide quick and highly dynamic response without turbo lag, while also ensuring the extremely smooth operation of the straight-six petrol engine. 

That’s all coupled to AMG’s quick paddle shifting Speedshift TCT 9G transmission with built-in double-declutching multiple downshift functionality and seamlessly variable front to rear variable torque split AMG Performance 4MATIC+ all-wheel drive and five driving mode Dynamic Select controllable via the optional Widescreen Cockpit.

The exclusive and luxuriously-equipped AMG 53 range adds a most compelling and perhaps class-leading contender to an ever-more intriguing middle performance market - certainly worth a look if you are looking in that neck of the woods… Michele Lupini