Mercedes-Benz A 45 AMG 2013 Review - International

What we liked:
?>> Cracking, strong four pot?
>> Engaging, stable handling?
>> Rich interiors

The CLA AMG combines tremendous power, brilliant mid-range flexibility, terrific interior comfort, a (mostly) slick gearbox and a great ride and handling compromise. It is no Friday night hotrod, either, because it does all of this with an interior trim level that sits well above the standard Mercedes-Benz fare.

Indeed, you could argue that this is a Mitsubishi Lancer Evo or a Subaru WRX STi for adults, combining all of their performance (adding some more) and lowering the noise, vibration and harshness levels, adding ride comfort and upping the luxury on everything in the cabin that you can see and touch.

Did we mention power? With 265kW from just 1991cc, it’s not just the most powerful four-cylinder car in the world, but the only production car with a better specific power (horsepower per litre) figure than the McLaren P1!

Besides being AMG’s first four-cylinder car, the CLA 45 is also its first tranverse-engined production car and its first car based off front-wheel drive architecture. So, just a few new things to tackle, then.

And they’ve been well tackled. This is a 450Nm machine that sprints 0 to 100km/h in 4.6 seconds and is limited to 250km/h. It has a 60:40 front-to-rear weight distribution, but a powertrain that can send more than 50 percent of the drive to the rear axle.

And it has a launch control system. And it is good.

And then there’s the hatch version… Just as the CLA sedan/A-Class hatch became Benz’s small answer to the E-Class/CLS twins, so it is with the AMG versions.

Identical in all but body shape, the A 45 AMG has the same engine, the same gearbox, the same wheelbase, the same suspension architecture, the same… Well, you get it.

The only differences, really, are that the A 45 has a slightly firmer damper setting (though it’s more of a character thing and so ‘slight’ that it can’t even be seen on a data trace) and a slightly louder exhaust.

Both of those things are cancelled out if you order the optional sports exhaust and sports suspension settings, which bring both cars back to utterly identical. There is still a difference, though, because the bodyshells have slightly different bending and torsional numbers and the hatch is around 30kg lighter at 1555kg.

Other than that, you’re looking at the differences in rear packaging (you are far less likely to bang your head getting in to the back seat of the A 45), and the hatch has far less luggage space (341 litres plays the CLA 45’s 470 litres).

The hatch is also almost a foot shorter (4359 to 4691mm), so it’s easier to park.

They might be mechanically identical, but they’re philosophically miles apart.

Anybody who said even five years ago that an A-Class would provide the young, new blood at Benz would have been laughed at. Now the A 45 has been tasked with bringing in the younger buyers, delivering a more aggressive handling package and swinging Germany, the UK, Japan and Australia the way of AMG.

It’s also the AMG that has the wildest of the launch editions, with the big rear wing, front aero flickers and that garish stripe down its length.

Actually, it looks like the material on the Alfa MiTo dash.

It takes everything the CLA throws at its buyers – like the optional doohickey to integrate a smartphone (provided it’s made by Apple) into the car’s own entertainment system – and adds more. For starters, the stock car’s shifter has been ditched for the Affalterbach loopy thing (which they call an E-SELECT lever). All of the trim around the instrument panel gets a unique look, plus there are flashes of colour inside the air vents themselves.

The instrument cluster has been tweaked to house the AMG Race Timer and a few other AMG-specific screens and the steering wheel gets the full factory treatment as well.

The car benefits from much of Benz’s investment in collision prevention aids and includes systems that figure out the braking force needed to avoid a crash, regardless of how much the driver miscalculates what’s needed.

There’s also the drowsy driver assistance system and radar cruise control, plus air conditioning and the usual array of seat and steering adjustments.

It scores a pair of rectangular tail pipes, each housing two exhausts, on the back, along with being lowered and running larger wheels and tyres. And you can get a big wing, if that’s your go.

Pitched and priced to sit beneath the C 63 AMG, the CLA 45 is actually a small car that is being pitched to sit beneath the C-Class sedan. The trouble is that at 4691mm long it is actually 61mm longer than the stock CLA and only 16mm shorter than the C 63 AMG, yet lacks its rear room.

So it’s a transverse-engined sedan that is longer than the stock C-Class, but with less interior space thanks to a wheelbase 61mm shorter (than the C 63’s 2699mm).

The short version of all of this is that it is supremely spacious up front, to the point that you can stretch the passenger seat back so you can barely touch the kick panel.

You won’t be that happy in the back seat, though. It’s tricky to get in and out of without hitting your head and there’s not that much room – or visibility – anyway.

There is a hole in the rear subframe for the tailshaft this A/CLA 45s were going to need, for example, and there are pieces of front suspension geometry that AMG’s engineers demanded that basically had no impact on the cooking Benzes.

It wouldn’t be an AMG without an outrageous engine. And this is an AMG.

Its first efforts for this car’s four-cylinder engine were not turbocharged. Instead, it was focused on pushing a pulse-charge setup that was a development of the Swiss Comprex system, though the AMG version was so much more advanced that it took to calling it Hyprex. It involved using the exhaust pulses themselves to force feed the engine. It worked, with no friction losses and no weight or cooling demands, but it had issues that just couldn’t be overcome.

That, of course, was already deep in the development cycle, which had AMG scrambling to develop this 2.0-litre engine in less than three years.

The most powerful four-cylinder engine in the world, with a phenomenal 133kW per litre, it has ended up with 265kW at 6000rpm, 450Nm at 2250rpm and will propel both AMG A-cars to 100km/h in just 4.6 seconds.

It reads like a who’s who of go-fast automotive parts, including a twin-scroll turbocharger with up to 1.8 bar of boost, centrally located piezo injectors. These deliver multiple injections, backed up with multiple sparks, per ignition for clean burning and massive power.

Its block and crankcase are both sand cast and it scores tougher, lighter bits like forged pistons, a forged steel crankshaft and sodium-filled valves.

To this it attaches a big-bore exhaust system, complete with a short-circuiting, electronically controlled sports flap for more noise and energy, and finishes it with a pair of chromed AMG exhaust tips.

There is also a huge front water-air intercooler with a supplementary cooler in the front wheel arch. A transmission cooler is built into the main radiator and has its own supplementary heat exchanger attached directly to the transmission.

Its internal engineering architecture is essentially the same as you’ll find on the 5.5-litre AMG V8 and deliver a burn so clean that it posts an NEDC combined fuel economy figure of 6.9 litres/100km and emits only 161 grams of CO2/km.

AMG builds the engine on its own dedicated assembly line at Benz’s Kölledo plant in Germany, under the same roof as all of the A and B-Class petrol engines, but it’s a lot more complicated than they are.

It won’t just deliver power, either, with the under-square 1991cc four pot delivering 450Nm at just 2250rpm and plateauing until 5000. It also still revs to 6700 rpm and weighs 148kg fully dressed.

This attaches to a seven-speed dual-clutch transmission, governed by the same brain AMG uses in the SLS.

It usually runs as a front-wheel drive, except when it gets slip. Then it sends up to 50 per cent of its torque to the rear axle effectively instantly (it could, theoretically, send more, but the axle can’t cope with it).

The rear diff contains a multi-disc clutch pack that’s fed by a two-piece prop shaft and the hydraulic pump controlling it is constantly driven. Unlike other part-time all-wheel drive systems, that means the A45 doesn’t have to wait for the computer to switch the rear diff’s hydraulic pump on and, when you’ve switched the stability control to the sports setting (or, even better, OFF!) it pre-engages more rear drive.

The suspension, too, is barely recognizable as an A-Class item. It uses a three-link front end with stiffer bearings, while a four-link rear end scores stiffer bearings and new struts.

This all rides on 235/40 R18 rubber at all four corners, with 350mm x 32mm front discs and 330 x 22mm rears, though there is an optional 235/35 R19 wheel and tyre option.

The thing is that while the CLA looks and feels more like the grown-up’s version, the A 45 is demonstrably more agile yet loses little to its 30kg-heavier sibling, except some of its ability to sneak under the visual radar.

The twins aren’t cars defined by its numbers (even if the launch-control system is easy to use and makes snapping out the 4.6-second bursts a lot of fun), but by the way they do what they do. From rumbling low and deep with the car set to Sport mode to cruising silently and comfortably on the backroads at 90km/h, it doesn’t seem to matter, especially to the CLA 45.

That’s the version that lends the impression of being more formal, but it’s a false impression. You don’t have to prod the party pedal too hard to find a stiff growl rising from the four pot and a sedan ready to throw itself up the road at a moment’s thought.

In the two (of three) sportiest modes, the gearbox snaps through each upshift reliably and fast, with a crisp, hard-edged crackle from the exhaust on the way through.

It’s fast and it’s flexible, pulling top gear easily from 1100rpm, reaching beyond 180km/h in fourth and easily resting on its 250km/h speed limiter.

But the chassis is the real highlight, carrying stupendous pace into sweeping country bends and punching out again with delight. There’s a sheer sophistication to its chassis setup that defies any lingering thoughts of AMG as just the purveyors of more power. It’s genuinely brilliant on broken country, even if it’s not as crisp as its brother.

On the frightening new Bilster Berg track near Hannover in Germany, the A 45 proved it could be picked up and hurled at a racetrack that verged on the ridiculous and it could haul in mid-corner time to a professionally driven SLS.

The big V8, naturally, skipped away anytime the road went straight, but the track (a new, vertiginous private race resort) has so many crests in the middle of its corners that, as the SLS pilot said, he had to drive in three axes.

Not so the A45. You could throw it into the corner and trust the chassis to gather everything up, even as you were already torturing it with extra torque pumping to all four tyres.

It could have its weight lifted right off the wheels and still barely lose traction and it felt pretty idiot proof, regardless of how hard it was pushed.

Its brakes are stupendously strong, too, and the steering, though accurate enough, is perhaps its only let down. It’s just not as precise as the rest of the package.

The real beauty of the A 45 chassis is that it managed to walk the fine line between being engaging, rewarding and inviting without feeling tiring, over-stimulating or utterly remote.

It’s a feeling the car carried on to the road, too, flitting through switchbacks with an ease and a refinement that only reinforced opinions that it’s a grown-up rally rocket.

The CLA is a true AMG car but it’s not as wieldy as its hatch counterpart. So, if you must take just one, make it the A 45. It loses very little in refinement and ride, but delivers a lot, lot more when you’ve really got it pinned.

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