Mercedes-AMG A45 S 2024 review – still a foil for the Audi RS3?

The Mercedes-AMG A45 S has gone from a token premium hyper hatch as laden with performance as it is unladen with personality, to a real firecracker with bite to match its bark and depth to its dynamic repertoire. It impressed on initial acquaintance and has done so repeatedly, staying on form, if losing a bit of steering feel, once facelifted. Then it over-delivered relative to expectations in our hot hatch mega test, where it ranked only below the scintillating Honda Civic Type R, the Toyota GR Yaris and the now defunct Hyundai i30N.

The updates for the facelift were subtle, with new headlights, a revised AMG-specific grille, and an Affalterbach coat of arms atop the nose instead of a three-pointed star. The AMG Performance steering wheel was new too, with new software running within the unchanged Mercedes A-Class physical hardware.

Underneath the A45 S retained its M139 turbocharged 2-litre engine, which is still one of the most powerful four-cylinder production engines in the world, behind the electrified 469bhp unit in its big brother, the Mercedes-AMG C63 E Performance. Its unchanged 415bhp peak is still absurd for a hot hatch almost four years on from its launch and still beats the unchanged 2025 Audi RS3’s five-cylinder by 21bhp. Both generate 369lb ft of torque for their four-wheel-drive systems to manage, the A45’s 4Matic+ providing a dual-clutch pack on the rear axle to allow for the de rigueur Drift mode.

Alongside the RS3s, GVW Golf Rs and Civic Type Rs of the hyperhatch world, the A45 S has always delivered the biggest performance punch, along with a look that gets close in terms of in-your-face aggressiveness to the Honda’s. Front-end dive planes, a prominent splitter, deeper sides sills, a rear diffuser and a roof-mounted spoiler are the AMG’s signature uniform, along with a set of 19-inch black alloy wheels. It doesn’t do subtle.

For all its punch the engine isn’t the dominant force you might expect, because the whole package is so well strung together. The transmission initially slurs as you’d expect of an automatic, while the engine and exhaust sound have been toned down with a particulate-filtered flatter-than-anticipated soundtrack when you leave the drive mode in Comfort; if you weren’t sitting in a winged-back seat (itself not to all tastes depending on your sensitivity to firmness and lumbar settings) and gripping that new steering wheel you might not even realise you’re driving an AMG. Thankfully, where Sport settings once were best left to the circuit or ultra-smooth road surfaces, today their calibration provides a far greater operating window, and the A45 S is no different.

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Engaging Sport tightens the dampers, loosens the engine’s shackles, tenses up the gearchanges, opens the exhaust and starts to relax the stability and traction systems, although the steering remains untouched. And the A45 feels much closer to its maker’s intentions as a result, its engine more alert with enlivened vocals and response times more befitting of a 400-plus bhp hatchback. The opportunity to crash into the hard rev limiter in lower gears is more forthcoming. The additional tightness through the body dials in more confidence, the firmer damper rate complementing the set-up without crashy results. On UK roads, the A45S can compose itself and cosset in the right measures. It’s the A45 as expected: sharp, decisive and blisteringly quick. 

Happy to be bullied into a corner or placed with a sports car-like deftness at the apex, the rewards are the same either way: grip from the Michelin Pilot Sport 4 S tyres seemingly unbreakable at the front, the rear mobile on command but with an ability to remain calm under immense pressure, with clean transitions from grip to low-level slip. 

As with its predecessor, with each passing mile thoughts of mid-nineties and early noughties Japanese Group A road warriors flood your imagination; you can’t help but wonder if AMG’s R&D centre has a handful of RA Imprezas and Mitsubishi Evos under dust sheets having served their time as inspiration for the A45. Quite the compliment, given the A45 S weighs a sturdy 1662kg, which is some 200kg more than the current Civic Type R, nevermind the aforementioned ‘90s featherweights.

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Where a Golf R starts to feel numb the harder you push, an A45 bubbles with a next level of enthusiasm, and where the latest RS3 relies on its oh-so-clever RS differential to bring fun, the A45 feels more organic, the more natural at wanting to leave a corner with a quarter turn of corrective lock as you feed in the throttle as the nose locks in on the apex. It uses its tech in a more natural way, blending it with a clarity rivals can’t match. The result is a car that’s eager to have the rear on standby on turn-in, load it on the way through and be poised to deliver blistering yet balanced traction on the exit.

When you want more from that explosive engine, Sport+ and Race deliver the feral responses to the throttle, but both introduce a chassis setting that can be too much for the road. While the Individual mode allows you to customise to your tastes, the Sport+ setting isn’t as harsh as it could have been. Looser traction and stability settings arrive here too and allow more freedom from the rear axle, but this only highlights what is of almost unanimous note among the evo team: a lack of meaningful steering feedback. The steering leaves you to place a lot of faith in the tyres’ performance as opposed to providing the detail to make clearer decisions. Really, it’s the main blot in the A45 S’s dynamic copybook, that sees it struggle, even in a rapidly thinning field of alternatives.

Indeed as the hot hatch as we know it continues to fade away, the A45 S remains a blazing advertisement for the sector. It’s bold and brash, and uncouth for many. At £63,445 it’s also too expensive, topping the price of entry for a new Audi RS3 by almost £4000. Nevertheless, for those who love the intensity of the Civic Type R but fancy a glazing of German plushness to match the Audi RS3 and VW Golf R, the A45 S, even with its remote steering, is in a class of one.

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Price and rivals 

£63,445 is big money regardless of the car, more so when it’s one that’s based on a humble hatchback, but the world’s most powerful four-cylinder production engine and the brain power of AMG doesn’t come cheap, so neither does the new A45 S. 

Alongside the best in class £50,700 Honda Civic Type R, the AMG will be hard to justify for many, unless they want or need an auto gearbox and four-wheel. If you do, the A45 S has the £43,895 VW Golf R covered – the £59,500 RS3 runs it close but not close enough to bloody its nose. If you do want a manual gearbox, rear-wheel drive sports car and only need two doors, there’s always the new £65,915 BMW M2.

2024 Mercedes-AMG A45 S specs