Mercedes-AMG CLA 45 S review

Just because you’re in the market for a seemingly sensible saloon or estate, there’s no need for driving to be a chore. Not when, among the fuel-sipping hybrids and down-sized petrol engines on offer, there are cars like the Mercedes-AMG CLA 45 S.

Now, having a 2.0-litre petrol engine sitting under the CLA 45 S’s bonnet might not seem all that special, but this is no ordinary Mercedes CLA. The engine is hand-built using racing knowhow to produce a mighty 415bhp.

With four-wheel drive and an eight-speed automatic gearbox, the CLA 45 S can hurl itself from 0-62mph in 4.1 seconds. Its four-wheel drive system does more than provide great traction – it also has a rear differential that can vary the amount of power sent to each rear wheel, improving agility and allowing AMG to build in a thoroughly mischievous drift mode.

Those performance car aids don’t come at the expense of practicality – you still get four doors, five seats and a big boot. A CLA 45 S Shooting Brake (read stylish estate car) version is available too.

When you comes to rivals, one car stands out more than any other: the Audi RS3 Saloon. Of course, you might also find yourself looking at the less practical, two-door BMW M2 Competition or the larger and more practical Audi RS5 Sportback for a similar price.

Let’s find out whether the (rather elaborately named) Mercedes-AMG CLA A45 S can out-run its opposition...

Let’s start with the obvious: the Mercedes-AMG CLA A45 S is ridiculously fast.

With launch control engaged on a dry road, there's barely a single horsepower wasted as the car hunkers down and fires you forwards like few other cars on the road. We didn’t have our timing gear with us, but we can fully believe the official 0-62mph time of 4.1 seconds.

Let’s face it, though, you’ll probably use launch control a handful of times to entertain friends. What really matters is how the car behaves when you just put your foot down and accelerate.

Whether you’re stationary or moving, there’s the briefest of hesitations before the CLA 45 S rockets forward ferociously, firing through its gears swiftly yet smoothly. The auto gearbox has a manual mode, which is faithful to your inputs, but it doesn't have the same level of interaction as the optional manual gearbox on the BMW M2 Competition.

Don’t expect the power to arrive all of a sudden like in some heavily turbocharged cars – this is an engine that thrives on revs.

Peak power doesn’t arrive until a heady 6750rpm, while peak torque arrives at between 5000-5250rpm. That's not a hardship, though, because you’ll enjoy how the turbo wakes up at around 2000rpm, and how the power increases in a linear fashion all the way to the red line.

It doesn't sound as good as the five-cylinder Audi RS3, but it’s still pretty good for a ‘mere’ four-cylinder and makes using all the revs pleasurable.

If you’re reading this thinking the CLA 45 S could behave like a bear with a sore head in traffic, prepare to be surprised. In comfort mode, it's no harder to drive than a regular CLA and is happy to trundle along quietly. 

Even with standard adaptive suspension, it is much stiffer than the regular CLA and feels a little firmer than the closely related Mercedes-AMG A45 S hatchback.

Although it can be a little jarring over crumbling city roads, it's perfectly liveable once you’re up to speed on less craggy surfaces. Yes, you’ll feel expansion joints on the motorway and be aware of most bumps on a country road, but tight body control means it never gets bouncy or uncomfortable.

We’d hazard a guess and say that those interested in the CLA 45 S will enjoy the odd B-road blast, so how does it behave?

Well, although its steering isn’t exactly bristling with feedback, you do get some sense of grip from the front tyres once you’ve got a little bit of lock on. Vitally, though, the weighting feels natural and it’s easy to place the car exactly where you want it on the road.

Even in comfort mode, body lean is minimal, although you can happily ramp it up to sport mode without it wanting to bounce you off the road. Not only does that limit lean and help it feel more eager to turn in, it starts to alter the behaviour of the rear differential.

Sport + and Race suspension settings are too stiff unless you’re on the smoothest of roads, but you can soften things off in the more extreme modes if you want.

Most normal driving is done with front-wheel drive, but the back wheels always seem happy to receive plenty of power to help maximise traction. When you push harder, you can feel the rear tyres dig in and help steer the car out of a bend.

In Race mode, the rear differential becomes even more aggressive, allowing you to neutralise any mid-corner front-tyre slip with a big dollop of power.

Then of course there’s Drift mode. It doesn’t make the CLA 45 S rear-wheel drive like the Drift mode on the bigger Mercedes-AMG E63 but it does help the car slide sideways easily when you accelerate hard and steer into a bend. Given its propensity to destroy tyres and its unsuitability for road use, it’s really an interesting gimmick and nothing more.

Driving overview 

Strengths Ferocious performance; entertaining handling; engine sounds good for a 2.0-litre

Weaknesses Stiff ride in more aggressive driving modes

In addition to the CLA’s already striking interior, the Mercedes-AMG CLA 45 S gets plenty of sporty touches, including a pair of AMG sports seats, an AMG flat-bottomed steering wheel with touchpad controls and AMG-specific graphics for the digital instruments. 

The driver’s seat has plenty of electric adjustment and combines with lots of steering wheel reach and rake adjustment to enable drivers of all sizes to find a comfy posture. 

You get a bundle of bespoke AMG software for the car’s MBUX infotainment system. It can show engine and gearbox oil temperatures, engine power output, record lap times and there's even a G meter to show acceleration forces. You can also log 80 separate feeds of data so you can analyse your on-track performance.

To display all that information, the CLA 45 S gets twin 10.3in screens – one directly in front of the driver in place of traditional instruments, with a touchscreen to its left.

Both have sharp graphics and the ‘virtual’ instruments are highly configurable yet remain easy to read at all times. You control them using the touchpad on the right hand side of the steering wheel, a system that can seem fiddly at first and takes time to get used to.

As for the infotainment system, you mainly control it by pressing the screen itself or the other fiddly small touch pad on the left of the steering wheel. It’s a good system with logical menus, but it's not quite as intuitive as the infotainment systems in BMWs.

Interior overview

Strengths AMG additions do make it feel even more special than the standard car’s interior 

Weaknesses Still doesn’t feel as robust as some rivals

The Mercedes-AMG CLA 45 S's standard-fit panoramic sunroof eats into head room for taller occupants up front, but there’s an adequate amount for a six-footer, despite its sleek coupé roofline.

There’s sufficient interior width to avoid having to cosy up to your passenger too closely, and the driver’s seat has enough movement to accommodate very long or exceedingly stumpy legs.

The front door pockets are big enough to hold a small bottle of water and a selection of travel snacks, and there’s plenty more storage elsewhere. Under the central armrest you’ll find a usefully large cubby, while the tray in front of the infotainment touchpad is perfect for a phone or wallet.

Back-seat passengers are not so lucky. Leg room is plentiful, but that dramatic roof line seriously eats into head room, and you’ll be rubbing against the headlining if you’re near six feet tall. The Shooting Brake version is a bit more accommodating, as is the Audi RS3.

Meanwhile, the coupé version has a useful boot capacity of 460 litres (similar to the regular CLA, depending on engine choice), but its high load lip and much smaller saloon-style aperture harm its practicality. The Shooting Brake has 505 litres and a less restrictive hatchback opening.

Practicality overview

Strengths Plenty of storage space; generous boot capacity; more practical Shooting Brake option

Weaknesses Limited head room

Make no mistake, this is a very pricey CLA. The Mercedes-AMG CLA 45 S costs considerably more than a top-spec Audi RS3 Vorsprung or a BMW M2. A limited-run Street Style Edition with more aggressive styling costs even more, just undercutting the Audi RS5 Sportback.

The CLA 45 S holds its value well, though (although not quite as strongly as the RS3), so private buyers should be able to find relatively competitive PCP quotes and get a healthy return when it comes to selling.

Although it’s unlikely you’d run one as a company car, it's worth noting that the model’s CO2 emissions figure of 203g/km puts it in the top 37% BIK company car tax bracket. The official 31.4mpg fuel economy figure will be tricky to match as well, if you frequently make the most of the performance.

The CLA earned the full five-star Euro NCAP rating back in 2019, with very high individual scores for adult occupant, child occupant and pedestrian protection. To help you avoid testing its crash-worthiness, the CLA 45 S comes with automatic emergency braking (AEB), lane-keeping assistance and a driver attention monitor.

The model did well in the 2023 What Car? Reliability Survey coming second out of 15 coupés, convertibles and sports cars ranked. Mercedes didn't do so well, finishing in 24th place out of 32 manufacturers. Audi came in 26th place, BMW came 12th and VW came in 22nd place.

Costs overview

Strengths Well equipped; holds on to its value well

Weaknesses High entry-level price

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