Hot Mercedes-AMG CLA 45 revealed to take on Audi RS3 Saloon

New 415bhp Mercedes-AMG CLA 45 will offer the greatest specific output of any production engine when it goes on sale in Autumn

This is the new Mercedes-AMG CLA 45. In the latest back and forth power struggle between Audi Sport and Mercedes-AMG, Affalterbach has fought back: the CLA 45 now outguns the RS 3 saloon with a total output of 415bhp.

That’s in its hottest S form (the only version the UK is getting), which can accelerate from 0-62mph in four seconds – 0.2 seconds faster than the RS 3. Top speed is limited to 168mph.

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That headline power output for the CLA 45 S is 20bhp more than the Audi, and 40bhp more than the outgoing CLA 45. Torque is up too, now at 500Nm. The increases come courtesy of a long list of upgrades to the outgoing CLA 45’s 2.0-litre four-cylinder turbocharged unit, which now offers the most horsepower per litre of any production engine.

Essentially one bank of the twin-turbo V8 used by the AMG GT, the engine’s upgrades include several features from the brand’s super coupe, including low friction bearings for the turbo and a special coating for the cylinder liners.

Among the other changes, the four-cylinder block has been spun around 180 degrees relative to its position in its predecessor’s engine bay, which moves the intake manifold towards the nose of the car, and the turbo and exhaust manifolds towards the back. Improved cooling, an improved two-stage fuel injection and larger exhaust valves in the cylinder head are also among the changes. The exhaust itself has internal valves which open to produce a more raucous soundtrack under hard acceleration.

Mercedes-AMG says that it has tried to give the engine a character more akin to a naturally aspirated unit. As a result, the twin scroll turbo is designed to minimise lag, while delivering peak torque quite high; between 5,000 and 5,250rpm. The rev-limiter, meanwhile, cuts in at 7,200rpm.

There’s a new eight-speed dual-clutch gearbox, and as before, power is deployed through all four wheels. The rear differential has a pair of clutches, one for each driveshaft, allowing for power to be metered out precisely between each of the rear wheels. This, according to Mercedes, not only helps traction but allows for the introduction of ‘Drift Mode,’ meaning that the CLA 45 will engage in the sort of lairy tyre smoking action that’s something of a trademark of Mercedes-AMG models.

To keep pace with the extra output, the chassis has received further attention too. The bodyshell is reinforced, while extra underfloor struts and a brace between the front suspension strut towers all allow a more rigid base to allow for more precise suspension and steering geometry.

Many of the suspension components are made from aluminium to reduce unsprung mass, the front track is wider, and the ESP system is able to nip the brakes individually to improve turn-in. These changes, according to Mercedes, are claimed to significantly increase cornering speeds.

From the outside, the CLA 45 gains a range of AMG specific upgrades. The CLA is separated from its hatchback A 45 cousin thanks to a subtle reshaping of the gaping front air dam, while the bonnet features a pair of ‘power dome’ bulges. The wings and arches are flared out further and house a set of 19-inch wheels. Behind those are a set of AMG brake discs, which at the front are gripped by six-piston calipers painted red.

Around the back, the rear diffuser is bookended by four tailpipes, each measuring 90mm in diameter, while a subtle lip spoiler sits on the boot lid.

Inside, the CLA 45 gets the usual AMG treatment. That means there’s a set of heavily bolstered front sports seats, with yellow highlights for the stitching and small panels of leather. The standard flat-bottomed steering wheel is trimmed in a mix of leather and Alcantara as standard, or there’s the option for either full Alcantara or leather only.

The MBUX infotainment system offers several AMG-specific displays, including one which positions a large rev counter right in the centre of the 12-inch digital instrument panel. In addition, there’s a unique gear indicator, a G-meter and lap timer. Take the CLA 45 to a track, and should the circuit be pre-installed on the system, the augmented navigation screen is able to display racing lines in real time.

The CLA 45 is set to make its public debut at the Goodwood Festival of Speed. Prices are to be confirmed, but it is expected to cost just over £50,000 when it goes on sale in the autumn.

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