Even BMW admits there is a fairly narrow band of SUV buyers interested in the fastback style the X4 offers, but it hasn’t stopped Benz and even Toyota from chasing it down this path.

Move past the philosophical points, though, and you’ll find the second-generation X4 to be a fine machine, with more rear legroom, better handling, quieter engines and a softer ride.

Much like the less polarising X3, actually.

You either get the X4 or you don’t. Yet for the people who do get it, they swear by its not-X3-ness. By its "sporty" advantages over the boxier version of the same chassis architecture. By how sleek it looks. And, perversely, even by how so many people don’t get it.

For all of its challenging philosophy, though, the first- generation X4 was a surprisingly good SUV, in the modern, soft-road idiom. And when the second generation arrives in SA in September, it will be all that and more.

It is refined beyond its initial ambitions, it has speed and assurance and handling that the gen one could scarcely have imagined possible and it’s upgraded in pretty much every area that matters.

It’s longer, wider and sits on a longer wheelbase, with more rear legroom. It has more luggage space, it’s cleaner through the air and it uses less fuel.

It will start in SA with three engines before adding another the M40d in January 2019, and it hopes to follow the first generation by having an unholy number of its sales tagged with M badges, which is where the money is.

Also, most of the 200,000 X4s already built were highly specified, so BMW moved the new one to a choice of three: an xLine package, an M Sport X package and an M Sport package, plus it can also tap into the Individual range of bits and pieces, too.

We spent time in two X4 variants — the xDrive M40d and the mid-level xDrive 30i. BMW SA has decided not to bring the 30i to our shores though, opting instead for the 20i, 20d, M40i and the M40d.

The fastest diesel is, indeed, fast, and strong, and unburstable, and, in the end, not quite fun. Massively competent, and quick in a straight line to the point where it slips beneath five seconds in the sprint to 100km/h, but not quite fun.

The turbo 3.0l, six-cylinder engine delivers 240kW of power at 4,400 revs, but the soul of the car comes from the 680Nm it crushes out from 1,750 and holds for another thousand revs.

That’s the whole crux of the argument, with the torque wave swamping every overtaking opportunity or corner exit, but taking any steering delicacy or handling nuance with it.

But it’s so impressive in what it does well. There is strength everywhere, as you’d expect, and the noise levels have been improved to the point where it sounds slightly sweet now, as well as muscular.

That can be improved even further by cracking open the bypass valve on the exhaust by pushing a centre console button or moving to Sport mode. The trouble with that is it becomes unpleasantly droning on constant-speed runs, like highways, so it’s best kept for around town overrun burbles and pops or for twisting mountain roads.

There is now 525l of boot space with rear seats in place. Picture: BMW
There is now 525l of boot space with rear seats in place. Picture: BMW

There’s little doubt that BMW gets more precise, clean, fast and smooth shifting out of the core ZF-sourced eight-speed automatic transmission than anybody else in the car industry, and that continues here.

It’s beautifully matched to the potent six-pot diesel, coping with all that torque without effort. It snaps through crisp shifts when drivers want to push on or use the paddle-shifting manual mode and it slips them through quietly at any other time.

It provides the powertrain with a classy pivot point, a reliable and flawless link between the engine and the all-wheel-drive system.

The tyre sizes have grown, with 245/40 R20 front and 275/40 R20 rear rubber flanking a four-link front suspension and a five-link rear end.

It’s an arrogant highway rumbler, overtaking with disdain, hurling you back and eating its way into holes that barely exist. It’s a little firm over lumpy bits of road, and as ever the dynamic modes are too firm for bumpy work and the suspension works best when left to its own devices in its default mode.

The noise reduction has been helped by the move to an acoustic windscreen across the board, while there are active louvres for the grille to keep air from swirling in the engine bay when it’s not needed for cooling.

The "M" bit of the badge on the M40d bestows on the diesel its own suspension setup, its own steering setup, some unique design elements and its own blackened exhaust tips.

There’s an M diff lock on the rear axle, stronger anchors with four-piston front callipers and the options of adaptive suspension and 21-inch wheels.

BMW claims it gets itself to 100km/h in 4.9 seconds. It feels faster than that, if anything, and its rolling acceleration feels bullock-strong.

Perhaps the biggest achievement is how few hints of coarseness enter the cabin from all that effort. There’s a pleasantly deep mumble at idle and when it’s cruising, and a bellow when it’s bruising out all that torque and not a single unwanted tremor makes its way to the seats or the steering wheel.

The limited-slip rear differential helps it to turn into slow corners briskly and punch out of them again. There’s so much weight (with 1,895kg of mass already there before people or fuel are on board) that it never feels alive or flighty, but it’s crushingly competent.

The X4 is outstandingly competent in pretty much every situation, though, except trying to carry as much luggage as an X3.

The 4,752mm overall length is 81mm longer, it’s 37mm wider (1,918mm) and its wheelbase is 54mm longer (2,864mm), while it’s just 3mm lower than before (1,621mm). That wheelbase stretch has added a bit to the front seat footwell, but mostly it’s been used to deliver 27mm more rear legroom.

For people who care about such things, the X4 now delivers 204mm of ground clearance, 500mm of wading ability, 25.7° of approach angle, 22.6° of departure angle and a 19.4° ramp-over angle.

It’s a dedicated five seater, too, and its 40:20:40 split-fold rear seat now has push-button operation and delineates a 525l cargo area. That seat folds down to create a 1,470l space, while the tailgate is push-button, key or kick operated.

The range has a new option in a version of the 7 Series’ enormous trick key, with its 2.2-inch digital screen. Even from a continent away, it can be used to see the fuel level and range, to lock the doors, close its windows or turn the heating on or off.

The interior is one of the major areas of improvement, adding to a list that includes a more comfortable ride, more reassuring grip and handling and reduced noise levels.

There is a fully digital instrument cluster — though BMW retains its affection for fixed semicircles in the middle of the screen for the tacho and speedo.

The infotainment screen stands at 6.5 inches, though the optional Navigation Professional setup brings a 10.3-inch touchscreen unit with it. The optional head-up display is full colour, fully adjustable for brightness and height and has a 70% larger screen area than before.

It brings with it an enormous range of driver-assistance systems, including an optional Driving Assistant Plus package that combines steering and lane control from zero to 210km/h (or almost the top speed of the 20i version).

It dials in active side-wind assistance, cross-traffic warning, crossroads warning and a setup to help drivers slot into parallel and 90° parks.

It’s a far better car than its predecessor. That much is clear.

It’s still an opinion polariser. That much is also clear.

And there are now more reasons to justify it than just being ornery or wanting a cut-down X6. But there aren’t too many reasons here to justify not just taking the X3.