AMG brings its A game
Mercedes aims to change opinions with its new 415bhp A45 S hot hatch
CONSIDER THE BAR RAISED. THE NEW Mercedes-amg A45 S has been revealed and it has a peak power figure of 415bhp. This is 1bhp more than the 996-generation Porsche 911 Turbo of 20 years ago could muster, a car that at the time challenged our perceptions of on-road performance. Yet here’s a small, premium hatchback, with five seats, a useable boot and a manufacturer warranty, that aims to bring that level of performance to the masses, or at least the masses who can afford a car with an expected circa-£50,000 price tag.
The A45 S will top the A-class range, with some markets (but not the UK) also getting a 381bhp non-s version. That 415bhp headline figure, which is 39bhp more than the old AMG A45 managed and is backed up by 369lb ft of torque, is thanks to an all-new 2-litre turbocharged four-cylinder engine. Putting to one side the engines in future hypercars such as the Koenigsegg Jesko and AMG’S own Project One, the A45 S motor has the highest specific output of any production car engine:
208bhp per litre. For context, the Mclaren Senna’s twin-turbo V8 manages 197bhp per litre, the Bugatti Chiron’s quad-turbo W16 184bhp per litre, and the Ferrari 812 Superfast’s naturally aspirated 6.5-litre V12 a lowly 131bhp per litre.
How AMG has managed to produce an engine with such an impressive capability is explained over the page, but it is just one part of why AMG says the new A45 will shed its predecessor’s lukewarm reception and be a real hot hatch star.
Work began right at the core, with a significantly more rigid chassis courtesy of new underbody stiffening braces front and rear, a new shear plate under the engine, a brace across the front strut towers and new L-shaped ‘shotgun’ braces on either side of those. The front track has been widened and accommodated with flared wheelarches, while AMG’S now-familiar ‘Panamericana’ grille adds to the A45’s visual aggression.
Exploiting this stiffer base, the engine sends its power to all four wheels via a heavily reworked version of Mercedes’ eight-speed dual-clutch
transmission. The basic all-wheel-drive system is similar to that used on other A-class models in terms of the hardware up front, but a new twin multi-plate clutch pack on the rear differential means the system is capable of actively splitting torque between not only the front and rear axles, but also the two individual rear wheels.
This has allowed engineers to create the increasingly ubiquitous ‘drift mode’, which when selected will facilitate Ford Focus Rs-style ‘drifting’. Outside of this mode it will allow more effective deployment of the engine’s considerable power and torque in normal driving circumstances.
What this new technology needs to do, though, is transform what was previously a flat-footed, characterless Top Trumps hatchback into something genuinely fun to drive. The new rear differential, and the slightly more playful mentality that goes with it, may finally yield results for a car that has so far managed to elude our affections, regardless of its performance capability.
The A45 S will be joined by a new CLA45 S too, with ‘45’ derivatives of Mercedes’ incumbent compact SUVS to follow soon after.