The two petrol editions of Mercedes’ small GLA crossover place greater priority on grip and, in ultimate form, utter grunt

Pros: Striking styling, strong powertrains, AMG enhancements up to sporting expectation.

Cons: Tight rear seat, 250’s awkward gear selector, thinly cushioned AMG chairs.

Scores: 4.1/5 GLA 250; 4.4/5 AMG

Mercedes do things differently with the GLA. The best edition to provide particular potential for off-seal adventuring, the diesel, cannot because it is front-drive only.

Meantime, it’s obvious the two petrol models that do come with 4MATIC all-wheel drive aren’t really dirt busters either. The $77,400 GLA 250 4MATIC and $99,900 GLA 45 AMG are, in look and driving feel, even more car-like – or, if you prefer, less crossover-ish – than that diesel entry package.

Indeed, the AMG edition is such a tarmac-hugging racer it’s fair to say if you ever saw one of those off-road you could automatically assume driver error was involved.

Well, that’s life in the modern and ever evolving world of soft-roaders, a place where all boundaries are broken, rules rewritten and nothing is as it seems. Still, the compact sector has been a great place to play this year and Benz has benefitted greatly; Audi and BMW have sold more cars, but Mercedes has enjoyed the biggest growth in market share and it’s highly likely the GLA and the impending next-size-up GLC will be its top performers of 2015.

Design and engineering:

Don’t be perturbed that the GLA, through being anything but boxy, strays from orthodoxy: In a category this crowded, new and different is an advantage. The cab-back shape might look smaller than some, but avoiding clichéd, class-normal bulkiness is also a plus.

There’s clearly strong DNA reference between this model and the A-Class hatch; an unavoidable as the second begat the first. The most obvious difference is increase (albeit modest, at a mere 30mm) in ride height and flared wheel arches.

The test 250’s bright blue paint job ensured it was the centre of more than one conversation. The 45 AMG, on the other hand tended to leaves gobs gaping for an entirely different reason.

Does a crossover really need a large roof-mounted diffuser wing? Maybe not, but this, the twin chromed exhaust outlets and those 20-inch rims – large for this size car but actually the smallest in the AMG inventory – certainly draw stares. Add in the model’s other special ingredient – an exhaust note straight out of 1980s’ Grouo B rallying, complete with snap-crackle overrun – and it’s a car that simply cannot be ignored. Too loud? At a track day, never. When sneaking home at 2am? Well, erm, perhaps.

Powertrain and performance:

Isolate your experience to the GLA 250 and it won’t disappoint. The direct-injected 2.0-litre petrol delivers 155kW/350Nm so is right up to snuff with class consideration. With this much power and traction it presents as being nippy and confident through corners and no slowpoke down the straights.

For sure, the zip comes more to the fore when the drive setting is removed from its default ‘eco’ position and reallocated to ‘sport’ and ‘manual’ modes. That also effects the fuel consumption but an on-test average of 8.4 litres per 100km, though 1.4L/100km short of official claim, is hardly something to cry over.

And the AMG is …? Well, you know the answer to that one. The outputs of 245kW at 6000rpm and 450Nm of torque between 2250 and 5000rpm are truly heavyweight accomplishments from a 2.0-litre four-cylinder.

The delivery is not without linearity, but with 0-100kmh in 4.8 seconds and nothing lost in wheelspin - thanks to the four-wheel-drive, some very classy performance rubber and a lot of AMG-created special pieces – it is certainly something of a rush. Employing the dual-clutch transmission in its "Race Start" mode for optimum acceleration makes it fast enough off the line to present as a pukka Porsche punisher, with blaring bimodal soundtrack to accompany. Don’t tell me you’re not tempted.

Drive appeal:

Impression that a pert dimension and slightly elevated – but still car-like - seating position makes the GLA a good choice for urban adventuring applies more to the 250 than the AMG, mainly because the latter is firm, frantic and … well, it just doesn’t much enjoy dawdling around town.

The sports model’s competition-style sports seats prove their worth when pushing along at pace, but are a little less comfy in the long run than the 250’s similar-looking, but better padded offers.

On the other hand, I much preferred the placement of AMG’s chunky gear shifter, between the seats, than the 250’s wand-style selector on the right side of the steering column. For right-hand-drive markets there’s always potential to occasionally mistake it for the indicator wand and flick it into neutral while ‘signalling’ a left turn.

Ride, refinement and quality:

The ride is quite good at 250 level and delivers in varying degrees of rigidity after AMG treatment, but put up with that and you’ll discover a chassis that delivers vivid thrills, with incredible agility and involvement, with a handling balance, steering feel and brake response more akin to a hot hatch than a high-rider.

What’s impressive is how planted the car feels through the bends in either format. It’s more resolved and better balanced with four-wheel-drive, whose electronics are so on the button they can send up to 50 per cent of drive to the rear axle in only 100 milliseconds.

Practicality and packagin:

It’s a beautiful cabin; quality lapses are difficult to find and there’s little sign of budget. The standard equipment list for any GLA includes nine airbags, dual-zone climate control, a powered tailgate, Active Parking Assist, bi-xenon headlights and a reversing camera. The 4MATICs adds in keyless go, the smarter COMAND infotainment and an electric sunroof that certainly lives up to the ‘panoramic’ descriptive, as it basically took up the entire roofline. Got to AMG and there are more enhancements, most aimed at performance use, such as the race timer function on the instrumentation.

Space-wise, the GLA is not quite snug, just short of spacious. The driver’s accommodation was comfortable enough for my lanky frame, but headroom is tight and the never-fail seat-behind-self test reveals the rear bench doesn’t quite leave the room to play with that most people associate with a crossover. Taller rear seat passengers will find longer trips a bit of a squeeze in the 250 and basically too tough in the AMG (its seats being bulkier) and the transmission tunnel also impedes.

When rear seatbacks are folded (virtually flat), they open up to 1235 litres of utility room; a good space for those who pursue active lifestyles.

How it compares:

Mercedes’ enthusiasm for tailoring the GLA across a broad spectrum is to be applauded; within the baby AMG cluster, it has as much verve and more versatility and the A45 and CLA45.

If practicality rates as highly as performance prowess, then the bucks might as well stop with 250. Add in the off-road pack and you’ll even get some enhanced off-seal ability.

As much as anything, the GLA wins favour for being incredibly un-SUV-ish in its look; it isn’t overly tall or expressively butch in appearance. The emphasis is on suave sophistication and it pulls this off really well.