The top-selling Mercedes-AMG A 45 S hot hatch and its CLA 45 S four-door coupe twin have both hit the market, priced at $93,600 and $111,200 (before on-road costs) respectively.
That’s a leap of between roughly $15,000 and $18,000 over the predecessor models which cost $78,240 and $93,070. However, Mercedes-AMG GmbH claims the impost is more than justified.
“We have completely redesigned our 45 models – from the engine and transmission through the chassis, the elaborately constructed drivetrain to the body structure and of course the design itself – all with one goal: to raise vehicle dynamics and the sporty driving experience to a level previously unimaginable in the compact class,” said the tuner’s CEO Tobias Moers.
At the heart of each is the world’s most potent full-production four-cylinder. The new ‘M139’ donk makes a peak of 310kW and 500Nm in each AMG S model that’ll be sold here (don’t worry about the 285kW/480Nm bases which we won’t get). That’s up 30kW and 25Nm on the old ones.
AMG claims a 0-100km/h sprint time of just 3.9 seconds for the A45 ad 4.0 seconds for the CLA, quicker by 0.3s and 0.2s respectively.
The engine has cool features such as a firewall-adjacent 2.1-bar twin-scroll turbo and exhaust manifold, two-stage piezo injectors, an electronically controlled wastegate, and multiple water pumps to cool the cylinder head and crankcase separately. The cylinder linings are coated in a patented Nanoslide mirror-like coating trickled down from F1.
Engine management’s ‘torque shaping’ moves the donk away from a flat table-like torque curve and instead delivers maximum torque higher up the rev band to offer a “more emotive driving experience” theoretically like a free-revving naturally aspirated drivetrain.
Like AMG’s BiTurbo V8 engines, the M139 is assembled by hand from a block, under its ‘one man, one engine’ principal. This means one person builds the engine over a period of 2.5 hours start-to-finish before it goes to bench testing, and affixes a signed build plate.
The standard transmission is an eight-speed DCT. The standard RACE-START function allows maximum acceleration from stationary, in a “highly emotive experience”. Control of the drive torque to both axles, and between the two rear wheels via the new diff, is electromechanical. On track, a new ‘Drift’ mode apparently enables power-sliding.
There are various AMG Dynamic Select drive programs from comfort to track that modify the throttle, shift times, AWD control, ESP, and suspension stiffness. There are also two active exhaust sound options with in-cabin ‘enhancement’, and electromechanical AMG speed-sensitive steering.
The brand new suspension gets adaptive dampers with multiple levels of stiffness controlled by button or dial. The brake package comprises 360 x 36mm front discs with six-piston fixed calipers, and 330 x 22mm single-piston (floating) stoppers at the rear. The car’s brain can also tell the mechanicals to brake the inner rear wheel in corners.
AMG “extensively reinforced” the body shell and changed the track and camber. An aluminium plate bolted underneath the engine, known as the "shearing plate", further increases the torsional rigidity at the front end. Diagonal struts front and rear of the underbody ditto.
The MBUX infotainment system comes with a gear speed indicator, warm-up timer, g-meter, race timer and engine data readout. AMG Track Pace software continuously monitors more than 80 vehicle-specific data points and displays lap and sector times.
The A 45’s visual cues include an AMG-specific radiator grille, wider front wings with flared wheel arches to create space for the wider front axle, and a front apron featuring a “jet-wing” design. Wider AMG side skirts visually lower it, while the rear view is characterised by two pairs of round 90mm-diameter tailpipes with internal fluting and AMG lettering.
With a wider front track from its CLA architecture, the CLA 45 S “has a naturally self-assured stance and does not require the same frontal flares as the A 45” apparently. But the coupe-design does share the A 45’s specific radiator grille. At the rear, it sports a diffuser with four individual fins, and a boot lid-mounted spoiler.
Standard features include a Burmester surround-sound audio system, an AMG Performance steering wheel in black Dinamica microfibre with contrasting yellow topstitching, heated and electrically-operated sports seats finished in two-tone leather, brushed aluminium trim, keyless-go and start, ambient lighting featuring 64 colours, dark privacy glass and a panoramic glass sunroof.
AMG-specific additions include the AMG Driver’s Package (with top speed increased to 270 km/h), the AMG Night Package with design elements in black, and 19-inch AMG cross-spoke alloy wheels in matt black with high-sheen flange.
2020 Mercedes-AMG A 45 S 4Matic+ $93,600
2020 Mercedes-AMG CLA 45 S 4Matic+ $111,200