Mercedes-AMG CLE 646 Spezialanfertigung revealed

MERCEDES-AMG has pulled the covers off its second Mythos-series special, the CLE 646 Spezialanfertigung, a track-honed, rear-wheel drive coupe built around a 475kW twin-turbo V8 and limited to just 30 road-legal examples worldwide out of a 250-unit total build.

Mercedes-Benz Australia has confirmed to local media that there are currently no plans to bring the car here - unsurprising given every example is understood to already be sold, alongside the cost and complexity of engineering such a low-volume special for right-hand drive.

Spezialanfertigung translates from German as “custom-built”, a fitting name for a car that starts life as a regular six-cylinder CLE 53 before being sent back to AMG’s Affalterbach headquarters to be stripped down and rebuilt by hand.

At the centre of the CLE 646 sits AMG’s heavily reworked 4.0-litre M177 EVO twin-turbo V8, tuned here to 475kW – or 646PS, hence the name – and 850Nm, available across a broad 2500-4500rpm band.

The engine’s flat-plane crankshaft trims rotating mass for sharper throttle response, and drive goes solely to the rear wheels via a nine-speed automatic and an electronically controlled limited-slip differential, the first rear-drive-only AMG V8 since the outgoing C 63 S.

A 48-volt mild-hybrid system, complete with a 17kW/250Nm integrated starter-generator, is carried over from other AMG models, though it is fair to say buyers of a car like this probably won’t be shopping on the strength of the mild-hybrid assistance.

Mercedes-AMG claims 0-100km/h in 3.9 seconds, 0-200km/h in 11.4 seconds, 0-300km/h in a claimed 36.2 seconds, and a 310km/h top speed – figures that comfortably eclipse the 330kW six-cylinder CLE 53 donor car, and even edge out the 450kW peak engine output (before hybrid assistance) of both the AMG GT 63 S E Performance and AMG S 63 E Performance, though those cars’ combined hybrid outputs are higher.

Peak torque of 850Nm falls just short of the S 63’s 900Nm.

Triple cooling circuits manage charge-air, transmission and 48-volt electrical temperatures, while a bespoke Akrapovič titanium exhaust handles both weight savings and the soundtrack.

Dropping all-wheel drive is central to the CLE 646’s diet, helping shed around 170kg versus the standard CLE 53 despite the heavier V8, for a kerb weight of 1895kg and a power-to-weight figure of 250kW per tonne.

Front-to-rear weight distribution sits at 56:44.

Carbon-fibre features heavily across the front guards, front bumper, side sills, bonnet, roof, rear bumper, and a reinforced boot lid, while rear and rear-side glass switches to polycarbonate and even the 12-volt starter battery has been lightened.

An integrated roll cage adds torsional rigidity despite the deleted rear seats.

The body itself grows a substantial 60mm wider at each axle over the standard CLE, riding 22mm lower up front and 16mm lower at the rear, and rolls on 20-inch wheels measuring 11 inches wide at the front and 12 inches at the rear, wrapped in 305/30 and 335/30 Michelin track tyres respectively.

Underneath, a steel coilover suspension developed with KW Suspension brings four-way adjustable dampers with independent low- and high-speed rebound and compression tuning.

Stopping power comes from AMG’s ceramic composite brake system, using 420mm front rotors with six-piston callipers and 360mm rears with single-piston floating calipers – bigger yet lighter than the standard CLE setup, and finished in gold.

Mercedes-AMG says “long-fibre” rotor technology helps dissipate heat faster to reduce fade under sustained track use.

Aerodynamically, the CLE 646 features a manually adjustable front diffuser with Street and Race settings, the latter using a Venturi effect to boost front-axle downforce; louvred front wheel-arch vents; channels beside the headlights that route air through the fenders; and a large, adjustable rear wing mounted on carbon-fibre supports bolted to a reinforced boot lid.

Mercedes-AMG quotes a drag coefficient of 0.402Cd in Street trim and 0.417Cd in Race mode, with the full aero package generating a claimed 250kg of downforce at top speed.

The car is finished in a fixed two-tone scheme, with Mojave Silver Magno up front transitioning to Obsidian Black from the B-pillar rearward.

Inside, the rear seats, sound system upgrades and automatic parking function have all been deleted in favour of a pair of ultra-lightweight racing bucket seats up front, carbon-fibre door panels and a flat-bottom AMG steering wheel wrapped in microfibre, with several driving modes and features removed to simplify its control layout.

The CLE 646 Spezialanfertigung follows the wild, screenless Mercedes-AMG PureSpeed roadster as the second model in Mercedes-Benz’s ultra-exclusive Mythos range, established as a sub-brand in 2022.

Pricing has not been disclosed, though given PureSpeed reportedly commanded around €922,000 ($A1.6 million), a seven-figure price tag for the CLE 646 would not be a surprise.

Mercedes-AMG has also confirmed a regular CLE63 – sharing a similar V8 but with more conventional styling – is in development as the effective successor to the previous-generation C63 V8 coupe, though its timing has not been confirmed.