Mercedes-AMG A45 review: World’s fastest hot hatch

Mercedes has restocked its hot hatch arsenal with an absolute weapon. Equipped with the world’s most powerful four-cylinder that produces mind bending performance.

The new Mercedes-AMG A45 burns with an intensity no other hot hatch can match — it’s a flamethrower among barbecue lighters.

With the world’s most powerful turbo four-cylinder under its bonnet, this small five-door has off-the-line acceleration to beat any obvious rival.

For the 0-100km/h sprint, this second-generation example whips existing all-wheel drive hot shots such as the Audi RS3 Sportback, Subaru WRX STI and VW Golf R. In A45 S form, it clocks less than 4.0 seconds for this benchmark of performance.

The A45 has the world’s most powerful four-cylinder engine.

And this means the Mercedes-AMG is only a few tenths of a second slower than exotic machinery from Ferrari and Lamborghini at more than four times its price.

Due in Australia early next year, the A45 should be about $85,000, a small increase over the previous model, launched in 2013.

Mercedes-Benz Australia is still negotiating with its German parent company and will announce an exact price closer to the local on-sale date.

The CLA45 sedan, in the past just as popular with buyers as the A45, will arrive about the same time. It’s technically identical to the hatch but the extra weight behind the rear axle means it’s fractionally slower. It will wear a higher price tag than the hatch, as before.

The A45 can sprint from 0-100km/h in just 3.9 seconds.

Mercedes-Benz Australia has decided already that it will take only the higher-powered version of the two 2.0-litre turbos developed by AMG specially for its new generation of small cars. The import will deliver a hard-to-believe 310kW, thus earning the “S” designation.

Hand-built by highly trained technicians at AMG’s Affalterbach headquarters outside Stuttgart, the engine is brilliant. The huge shove — enough to impress any V8 lover — through the middle of its rev range is just a prelude to the high-energy top-end of this high-revving 2.0.

Mercedes-AMG engineers say they tailored the engine’s performance so that the harder it revs, the more eager it feels and sounds. — and that’s the way it seems from the driver’s seat as it zings towards its 7200rpm redline.

The A45’s engine revs up to 7200rpm.

The sound is brassy and classy, thanks to opening valves in the muffler, but this doesn’t add the same degree of pop and fart from the quad exhaust pipes as in some other Mercedes-AMG models.

The engine naturally is the centre of attention but there’s way more to the A45 S story.

The eight-speed twin-clutch auto and all-wheel drive underpinnings fluently translate power into speed. (The new Mercedes-AMG A35 “entry model” is scheduled to reach showrooms late in the year with a seven-speeder.)

The A45 looks the part with its large rear spoiler.

The new A45 also has a new and fast-acting double-clutch rear axle. This helps during maximum-attack straight-line take-offs, as well as with cornering agility and drive.

Other A45 advantages over the A35 are a wider front axle, extra body stiffening and bigger front brakes featuring stronger motorsport-style mountings.

With a dozen vertical louvres filling its grille, there’s a clear visual link between the new A45 and larger, more costly AMG models. Broader front guards are needed to cover the wider front stance.

With standard 19-inch wheels and tyres and rear spoiler that’s part of an optional aero pack, the A45 S has the looks to go with its performance.

Inside gets sports seats and steering wheel.

Inside, the A45 S gets distinctive yellow highlights on its sports seats and steering wheel and extra AMG menu items on the instrument and infotainment screens.

Unsurprisingly, everyday driving isn’t where the A45 S shines. The ride is jiggly at low speeds, even with Comfort selected for the softest of the three settings in the optional-in-Europe adaptive shock absorbers.

Tyre noise is irritatingly high on the kind of coarse road surfaces common in Australia. And the rear view mirror is prone to image-blurring vibes at about 2000rpm.

These faults are easily forgotten when you point the A45 S at a challenging road and drive with vigour. The fierce four under the bonnet makes every short straight a chance to put on big-time speed.

This of course means using its excellent brakes to slow for the next bend, then using the precise steering to aim it for the apex of the corner.

The A45 is one of the best performance cars in the world.

Outstanding grip and drive mean there are few other cars — at any price — able to match the A45’s twisty-road pace, if driven well. It’s a scorcher of a car that will torch the opposition.

Mercedes-Benz A45 S vitals

Price: $85,000 (est)

Safety: 5 stars

Engine: 2.0-litre 4-cyl turbo, 310kW/500Nm

Thirst: 8.3L/100km (est)

0-100km/h: 3.9 secs

Put the boot in

There’s next to no driving difference between the A45 hatch and CLA45 sedan. The Mercedes-AMG stopwatch says the heavier four-door is a fraction slower, though they feel the same. The hatch wears slightly narrower tyres but corners equally well.