What's the news?

Mercedes-Benz has confirmed that the GLA 45 AMG will go into production - just months after a 'concept' version was shown at the 2013 LA Auto Show. Not that we're complaining; a 360hp crossover that can bloody the nose of the Audi RS Q3 and make life uncomfortable for the forthcoming Porsche Macan Turbo is very good news in our book.

Exterior

Because that LA concept was so close to this impending production version, the GLA 45 AMG is a familiar shape. Shorn of the racing livery of the show car, the GLA 45 is a solid-looking little thing, the 'slightly-chunkier-A-class' appearance working well when paired with the big, elegant alloys and rectangular quad-tipped exhausts (they're only twin-pipes behind, if you look closely) that are AMG signatures. Oh, and the GLA gets an AMG first - the discreet, offset badging in its radiator grille louvres that marks it out instantly as an Affalterbach product, something that will be carried over to all future models.

Interior

If you've been in either the A 45 or CLA 45 AMGs, it'll be familiar as long as you discount the elevated driving position. There's a pair of excellent bucket chairs in the front, with a three-spoke, flat-bottomed sports steering wheel with paddle shift for the driver - and there's red stitching across both seats and wheel, for a sporty ambience. AMG adds in its Drive Unit and displays, including Racetimer, which should promise performance-orientated visuals for all the major controls of the GLA.

Mechanicals

This is where the juiciest nuggets are to be found. The GLA carries over the hand-built (yes, really) 1,991cc turbocharged four-cylinder petrol engine found in the aforementioned A 45 and CLA 45 AMG models, which makes 360hp at 6,000rpm and backs it up with 450Nm between 2,250- and 5,000rpm. With a specific output of 181hp-per-litre, it's the most powerful four-pot in current series production and will punch the GLA from rest to 62mph in just 4.8 seconds, running on to the now-commonplace 155mph limiter. But on top of its rampant power, the 2.0-litre throws in some BlueDirect eco credentials as well with EU6 compliance, a quoted combined economy of 37.6mpg and CO₂ emissions of 175g/km. There's also a standard-fit sports exhaust system, which uses an active flap in the rear silencer to provide both refined cruising behaviour and madcap exhaust blare when pressing on, while a set of performance pipes will be an option.

The twin-scroll turbo engine - which boosts to a mighty 1.8 bar - is coupled up to Merc's Speedshift seven-ratio DCT automatic transmission, which has three shift modes and also a launch control function called Race Start. So confident of this gearbox is AMG that it references no less a car than the SLS AMG in the blurb, claiming the shift times of the GLA's system can match up to the super GT's.

Putting all this to the tarmac is the AMG 4Matic all-wheel drive system. This leaves the GLA in front-wheel drive under normal conditions for the purposes of economy, but it can shove 50 per cent of the torque available to the rear axle when required. There's also a three-stage ESP stability control system and Curve Dynamic Assist too - an understeer-quelling system that acts in lieu of a mechanical differential, braking the inside rear wheel to create extra yaw and theoretically provide the GLA 45 with sharper handling.

MacPherson struts at the front and a newly-developed four-link rear axle team up with AMG springs and dampers, bigger anti-roll bars and a rear sub-frame bolted directly to the body, all of which should hopefully bestow excellent dynamics upon the GLA. As with the exhaust, an AMG performance upgrade will be available. Vented, cross-drilled brakes with grey calipers (red is an option) are fitted, while the 'sports' steering is a speed-sensitive, variable ratio affair.

Anything else?

The GLA 45 AMG is aimed at a younger target audience than the more traditional products of both Mercedes and AMG, and the company decided to go ahead with the car following positive reception to the concept at LA. The result is that the GLA is the fifth AMG SUV you can purchase, joining the ML 63, GL 63, G 63 and G 65 variants. So, if you want a 4x4 that can go bonkers quick, your nearest AMG showroom has to be your first port of call.

And finally, the car will get its debut on January 13 at the Detroit NAIAS motor show, but if you can't wait until then, there's an interactive 'web special' where you can experience the GLA 45 AMG online. Go to www.mercedes-amg.com/webspecial/gla45 for more info.

Matt Robinson - 7 Jan 2014