BMW 428i vs Mercedes-Benz GLA250

What's the difference?

Tim Robson road tests and reviews the BMW 4 Series with specs, fuel consumption and verdict at its Australian launch.

Following on from the mid-life tweaks to BMW's mainstay 3 Series in December 2015, the spin-off 4 Series line has now been updated along the same powertrain and equipment lines.

Based on the same mechanicals as the 3 Series, the three-year-old 4 Series was ostensibly formed to give BMW's nomenclature some sense of logic by designating its two-door machines as 'evens' (2 Series, 4 Series and 6 Series) and its four-door cars as 'odds'.

Three variants currently make up the 4 Series range, including a two-door Coupe, a two-door Convertible and – oddly, given the naming regime – a four-door Gran Coupe that also sports a hatch-like tailgate.

Buuuuuuuur, parp, buuuuuuuuuuuur, parp. Anyone who knows anything about cars immediately recognises the sound of a 45-engined A-class derivative. It's the sound you hear in a tunnel as old mate blasts past with a giant carbon-fibre wing atop his hatchback. It's the sound you hear at 3:00am on a summer morning (if your suburb has no speed bumps, of course).

In short, that sound means big power from a 2.0-litre turbocharged engine, a seven-speed transmission, and a bunch of Germans who clearly had a sense of humour in charge of tuning the exhaust note.

Sure, the GLA compact SUV is probably a slightly unexpected source of all that noise. But then, Merc's Ingolstadt rivals stuffed Audi's stupendous five-cylinder engine into a Q3 to make the hugely improbable RSQ3, so why not do the same with their skirts-lifted A-Class?

To be honest, my expectations for this car were low. So do I owe Mercedes a grovelling apology? Or can I still claim the moral high ground after a week of GLA 45 "ownership"?