Mercedes-AMG CLA 45 S 4Matic+ (2020) review
The Mercedes-AMG CLA 45 S brings high performance to the compact four-door segment.
Dave Humphreys
Dave Humphreys

Published on July 30, 2019

Mercedes-Benz has decent form when it comes to producing four-door coupes, and now its second-generation CLA gets the full AMG treatment. The Mercedes-AMG CLA 45 S 4Matic+ name is a mouthful, but it packs an equally big punch thanks to a stonking new engine and advanced all-wheel-drive transmission.

In the metal

The evolution of the Mercedes CLA into its second generation brought with it a more mature design, adding sleekness and better proportions, becoming more like the smaller version of the Mercedes CLS. One of the differences for even the standard CLA was an increase in track width, so, while the AMG version does wear flared wheel arches, these aren't as prominent as on the equally-new A 45 hatch. The CLA does get unique styling treatment for the front apron, which was necessary to feed more air into the cooling system. This design sets it apart from the AMG-Line specification that has proven so popular on the regular Mercedes-Benz CLA.

In standard form, the AMG CLA 45 model wears 18-inch wheels behind which lurk 350mm front brake discs with four-piston callipers, and 330mm discs at the rear gripped by single-piston callipers. That model uses the 'M139' engine in a 387hp configuration, but opting for the CLA 45 S version driven here bumps the power up to 421hp and brings a series of other technical changes. These include larger six-piston brake callipers at the front with 360mm discs and 90mm diameter quad exhausts at the rear. Furthermore, buyers can add an aero kit from the factory. This alters the aero setup of the car to generate greater levels of downforce at higher speeds. Dive planes on the front bumpers and a taller spoiler at the rear also give the car a more aggressive and less subtle look.

Currently, the interior design game is strong at Mercedes-Benz, and the CLA is no exception. The cabin is all but identical to that of the A-Class range and the AMG version gets the best of equipment. That means the full-width dual-screen setup for the instrument display, which looks excellent with vibrant colours and sharp resolution. You get a choice of control for the infotainment system, through the touch-sensitive tabs on the multifunction steering wheel or the large trackpad on the centre console.

You do still need to watch your head on the sloping roofline when getting in, but there is slightly more space in the back of the CLA than its predecessor. The frameless doors add to a premium feel, and rear knee room is helped a little further by the thin sports seats in the front. Boot space remains the same as the standard CLA, at 460 litres, and two handy levers on the top of it make it easy to drop the rear seats.

Driving it

It would be easy to focus solely on that fantastic engine, but the key to this AMG's intoxicating appeal is how it delivers all that performance. Setting out in early morning city traffic shows the civilised side of the CLA. The car happily trundles along in commuter traffic and the brakes feel every bit as gentle as they do on the ordinary Benz CLA. Even the stop-start function of the engine is smooth and mostly quiet. You do have an active exhaust at hand, so if you prefer to draw less attention to yourself, you can keep it in a quieter setting.

The slender sports seats may be thinly padded, but they provide enough comfort for a couple of hours at the wheel. Only when you begin driving with more enthusiasm do you notice how good a job they do at holding you in place. You need them to do that job well given how much lateral acceleration the CLA can achieve. Even on the fast, sweeping Jarama track, there is barely a chirp from the tyres, which are a slightly wider 255/35 size compared to the 245s on the A 45. Powering out of slow hairpins the four-door coupe surges forward at an incredible rate. You can instigate some more dramatic rear-wheel-drift action with the Race mode. Due to the advanced software and precise nature of the new rear axle setup, it's easy to achieve and maintain some dramatic looking slides. That trick rear axle uses an electro-mechanically controlled multidisc clutch on each half shaft to vary the power delivery from left to right.

Equally impressive is just how much confidence that all-wheel-drive transmission gives you without sanitising the driving experience. With the sportier drive modes activated, it can feel more rear-biased when powering out of corners. However, it is the prodigious mid-corner grip that keeps rising to the surface as the standout feature. As you incrementally add more entry speed, the CLA soaks it up without a fuss.

Even after two packed days of driving, the addictive nature of that engine's performance failed to wane. It's the first engine in this size class that genuinely rivals the epic turbocharged five-cylinder Audi unit, but the CLA could also go giant-killing. For perspective, the Mercedes-AMG C 63 S saloon may enjoy an 89hp advantage, but the CLA 45's smaller package means it is only a tenth of a second slower to 100km/h, and with half the number of cylinders.

What you get for your money

Official pricing is yet to be announced by Mercedes-Benz Ireland, so we won't issue a score to this section. Going by the starting price of the 'junior' Mercedes-AMG A 35 at €59,245, it's entirely feasible that this car will be nearing €80,000 when it arrives on our shores. That's a lot of money for a car this size, and while its performance does go some way to justifying the price, it isn't that far away from AMG C 63 territory.


For now, the Mercedes-AMG CLA 45 has the high-performance end of the compact saloon market mainly to itself, aside from the ageing Audi RS 3 Saloon. But with new rivals coming in the shape of the BMW 2 Series Gran Coupe, and the possibility for an M version of that, this segment could get interesting in the near future.


Tech Specs

Model testedMercedes-AMG CLA 45 S 4Matic+

Engine2.0-litre turbocharged four-cylinder petrol
Transmissioneight-speed automatic, all-wheel drive
Body stylefour-door coupe
CO2 emissions189g/km (Band E, €750 per annum)
Combined economy34.0mpg (8.3 litres/100km)
Top speed270km/h (electronically limited)
0-100km/h3.9 seconds
Power421hp at 6,750rpm
Torque500Nm at 5,000-5,250rpm
Boot space460 litres
Rivals to the CLA 45 S 4Matic+ (2020)