Mercedes AMG A45 review

We all love a big headline figure, and in a game of Top Trumps the Mercedes AMG A45 is the best card to draw out of all the hot hatchbacks.

That’s because its engine develops a whopping 416bhp, which is a lot for a proper performance car, let alone a family-sized hatchback. Even more impressive is the AMG A45's official 0-62mph time of 3.9 seconds.

But this performance doesn't come from a big six or eight-cylinder engine – just a 2.0-litre petrol with four cylinders (oh, and a turbocharger bigger than your head).

Only one other hot hatch gets close to the AMG A45's manic performance: the Audi RS3. However, if you're in the market for a fast and fun hatchback, you might also be considering the cheaper and less powerful BMW M135 or Honda Civic Type R. 

So, is the Mercedes AMG A45 actually any good to drive and own, or is it just good for bragging rights? Read on to find out...

Let’s start with the obvious: the Mercedes AMG A45 is indecently fast. Its 2.0-litre four-cylinder turbocharged engine creates 416bhp – more than any other 2.0-litre engine in production.

With launch mode engaged (in the dry at least) hardly a single horsepower is wasted as the AMG 45 hunkers down and fires you forwards like few other cars. Even in the rain during our tests, it managed 0-60mph in four seconds – half a second quicker than a BMW M2 with a manual gearbox managed in the dry.

That’s all well and good, but more important is what happens when you plant your right foot on the A45's accelerator pedal without launch control engaged. With such a big turbo strapped to such a small engine, there must be a long pause before it provides any meaningful punch, right?

Wrong. Pin the accelerator to the floor and after just the briefest of hesitations the A45 rockets forward ferociously, firing through its gears as it does so. It delivers the kind of shove that just a few years ago was reserved for supercars with six-figure price tags. 

Another surprise is that this is a turbocharged engine that thrives on revs, with peak power not arriving until a heady 6750rpm. You’ll delight in how the power increases in a linear fashion all the way to the redline. True, it doesn't sound as good as the five-cylinder Audi RS3, but it’s still very tuneful for a four-cylinder.

For an even more engaging drive, you can press a button to put the A45's eight-speed DCT automatic gearbox in manual mode and change gears using paddles behind the steering wheel. It's pretty faithful to your requests, and certainly more alert than the RS3's gearbox.

Now, if you’re reading this thinking the A45 must be a temperamental beast that behaves like a bear with a sore head in traffic, prepare to be pleasantly surprised. Left in comfort mode, it's almost as easy to drive as a regular Mercedes A-Class and is happy to trundle along quietly.

The A45's standard adaptive suspension is firmer than a regular A-Class's, but only nasty potholes or recessed manhole covers cause any discomfort. Indeed, if you avoid battered surfaces, the AMG A45 is actually quite easy to live with by hot hatch standards, although the RS3 (when fitted with adaptive suspension, at least) is more agreeable and doesn’t jostle occupants around in their seat as much. The RS3 also generates less road noise on the motorway.

So, what happens when you turn away from straight roads and onto something more sinewy?

Well, the A45's steering isn't hyper-quick, but it gives you a much better sense of connection with the front wheels than you get in the RS3. The Honda Civic Type R has meatier steering that's better still but, crucially, the A45’s steering always feels natural and precise, making it a cinch to place it exactly where you want it on the road.

Even in Comfort mode, body lean is minimal, and you can ramp things up to Sport mode to further reduce it without completely ruining ride comfort. The Sport+ and Race suspension settings are a bit too much for all but the smoothest of roads but, if you wish, you can apply these most extreme settings to the engine and exhaust without affecting the suspension.

Like the less powerful Mercedes AMG A35, the A45 has four-wheel drive, but the latter has a much cleverer set-up. As well as varying the power split between the front and rear wheels, it can also vary it from side to side at the rear.

The aim? Well, depending on the drive mode you’ve selected, the system can boost traction – and therefore stability – so the rear wheels can receive plenty of power and help prevent the nose of the car running wide through corners.

Alternatively, you can use the 'drift' mode, which encourages the car to slide sideways easily when you accelerate hard and steer into a bend. It won't do the tyres much good and is unsuitable for public roads, but if you like that sort of thing it's a lot of fun.

“I know the AMG A45 isn't as civilised as an Audi RS3, but that’s also a big reason for wanting to wake up at the crack of dawn just to go for a blast in it. Hot hatches should always put fun first.” – Lawrence Cheung, New Cars Editor

The Mercedes AMG A45 gets plenty of racy touches in its visually striking interior to make sure it obvious you aren't in a regular Mercedes A-Class. These include a flat-bottomed steering wheel with dials for changing drive modes, and AMG sports seats in the front.

Although those seats don't have adjustable lumbar support, the driver's seat offers plenty of other electric adjustment as standard. The steering wheel also has a good range of height and reach adjustment to allow drivers of all sizes to find a comfy posture.

The A45 adds a bundle of bespoke AMG software to the MBUX infotainment system. It can show engine and gearbox oil temperatures, record lap times and there's even a G meter to show handling and acceleration forces.

Indeed, the system can log 80 separate feeds of data so you can analyse your on-track performance – although we doubt many buyers will use this feature more than once or twice. Like having a diving watch that's rated to 200 metres, it’s more about bragging rights than anything else.

On the dashboard there's a 10.3in digital instrument display behind the steering wheel, which butts up against a 10.3in infotainment touchscreen. Both have sharp graphics, and the digital instrument panel is highly configurable yet easy to read. In the A45, it also displays AMG-specific graphics and a large central rev counter.

Unfortunately, Mercedes has removed the useful touchpad that was found on the centre console in the previous-generation A45, so you now have to use the touchscreen or fiddly touch-sensitive buttons on the steering wheel to control the infotainment system.

However, at least the operating system is easy to get to grips with, with logical menus and quick reactions to all of your inputs.

The AMG A45 also looks the part inside, thanks to a range of eye-catching details, including turbine-style air vents that light up and glow like afterburners at night. That said, build quality could be better; the Audi RS3 and BMW M135 feel better screwed together.

“I love that you can adjust how the AMG A45 drives using controls on the steering wheel. It saves you faffing around with the touchscreen.” – Dan Jones, Senior Reviewer

Put simply, the Mercedes AMG A45 is just as practical as any other Mercedes A-Class. That means plenty of space up front for a couple of 6ft-plus adults as well as decent storage.

A couple of tall mates will fit in the back, but can expect to find their knees fairly close to the seats in front. This is also the case in the rival Audi RS3, and while the Honda Civic Type R offers significantly more leg room, it's actually worse for head room.

There’s nothing spectacular about the A45's boot, although it’s quite a bit bigger than the RS3's and capacious enough for a decent load of shopping or luggage for a weekend away. In our tests, we managed to slot six carry-on suitcases below the parcel shelf, compared with only four in the RS3.

The lip at the boot entrance is a bit annoying because its presence means you have to heave heavy items over it rather than simply sliding them in or out. There’s no height-adjustable boot floor, either.

“The AMG A45 has four-wheel drive, and I think it's impressive that the system hasn’t eaten into boot space.” – Neil Winn, Deputy Reviews Editor

The Mercedes AMG A45 is one of the most expensive hot hatches you can buy, costing significantly more than the BMW M135. Even the Audi RS3 is available for slightly less.

The A45’s CO2 emissions are high enough to put it in the top 37% bracket for company car tax, although the same can be said of its direct rivals. If you want a hot hatch with a low BIK tax rate, we'd recommend checking out the fully electric Hyundai Ioniq 5 N.

Meanwhile, the A45’s official 31mpg fuel economy figure isn’t bad for a car this quick, and in our real-world tests it still averaged a respectable 28.5mpg.

There are two trim levels: Plus and Legacy Edition. Plus gets you plenty of equipment, including 19in alloy wheels, ambient interior lighting, a sunroof, climate control, cruise control, a Burmester sound system, heated front seats, wireless phone-charging, front and rear parking sensors, and a 360-degree view parking camera.

The Legacy Edition is a limited-run model, and has bespoke Green Hell Magno paint and black and yellow alloys wheels. There are some yellow interior highlights, too. 

Mercedes came a rather disappointing 22nd (out of 32 manufacturers) in our 2024 What Car? Reliability Survey league table. For comparison, Audi finished 24th and BMW was eighth. The A45 comes with a three-year warranty with no mileage limit, the same level of cover you get with the BMW M135. The Audi RS3 gets a three-year warranty, too, but limited to 60,000 miles.

The five-star Euro NCAP safety rating awarded to the regular Mercedes A-Class doesn't apply specifically to this A45 version, but it's encouraging nonetheless. Automatic emergency braking (AEB), lane-keeping assistance, blind-spot monitoring and driver attention monitoring are fitted as standard.

“I think it’s a shame the bright yellow paint option is no longer available for the A45, but there are some interesting alternatives, including Mountain Grey with a matte finish.” – Dan Jones, Senior Reviewer

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