Whatever happened to normal cars – you know: plain old sedans, or estates, or SUVs? These days, it seems, there are no rules: coupés can have four doors, hatchbacks can be SUVs, and SUVs can be sports cars.

BMW has a track record of breaking the rules. After all, it created the X6 – a strange conglomerate of 4×4 and sports coupé that it calls a Sports Activity Coupé. When that vehicle first arrived, I was convinced it wouldn’t fly, but 250,000 global sales later, it’s very much a success story. No wonder BMW is bullish about the prospects of the all-new X4.

As the nomenclature suggests, the X4 is a smaller version of the X6. Or, to be more accurate, it’s a four-door coupé version of the X3 SUV, very much like the X6 is based on the X5. In other words, the X4 employs the underpinnings of the X3, but marries them to a more streamlined, more eye-catching shape.

BMW remains unique in offering models that straddle the seemingly incompatible genres of 4×4 SUV and sports coupé. But in some ways, the X6 – and now, the new X4 – recognise what we already know: that most buyers of premium SUVs have no intention of venturing off the beaten track.

Instead, fancy 4x4s are acquired because of the illusion of security created by their raised stance, the extra traction of their all-wheel drive systems, the luxury of their premium-grade interiors, and the space and practicality of their SUV cabins.

Let’s not forget that these urban warriors are great when it comes to mounting kerbs, or parking on pavements. But bundu bashing? No way…

Despite its extra ground clearance suggesting that it would probably tackle mild off-road terrain with ease, there’s no pretence that the X4 is an all-terrainer. The styling is more city slicker than dune raider.

In true coupé fashion, the roofline draws a graceful arc from front to rear, while the big alloy wheels are aptly dressed with ultra-low profile performance rubber. The X4 swaps the angular, purposeful look of the X3 for altogether sleeker, sassier lines. And yes, it does look just like a junior, trimmer X6.

Lest we forget that at least half of the newcomer’s personality is focused on sporty dynamics, the front end is adorned with big, hungry air intakes, while the stare of the slender headlights on either side of the trademark kidney grilles adds malevolence to the BMW’s facial features.

In profile, the emphasised contours of the widened wheel arches, the pronounced shoulder line and the scalloped flanks, all contribute to the X4’s visual muscle, underpinned by those big wheels. At the rear, L-shaped LED tail light clusters, a slanted tailgate and a deep apron with asymmetrically positioned twin exhaust tailpipes continue the dynamic theme.

Anyone familiar with BMW interiors will feel instantly at home in the X4’s cabin. From an ergonomic perspective, the design and layout is unmistakably Bavarian, with driver-focused ergonomics, high tactile quality levels, and a sense of lavish luxury.

In deference to its quasi-sports coupé identity, the X4 seats its front occupants 20mm lower than in an X3, while the curve of the roofline appears to threaten rear headroom, making for slightly cosier rear accommodation.

The seat itself is split 40:20:40, which allows a particularly versatile range of seating vs. cargo combinations. The boot is a generous 500 litres with all seating positions available. Fold the rear seats flat, and the cargo capacity increases to a more than respectable 1,400 litres. Access to the luggage compartment is via a wide-opening, motorised tailgate that opens and closes at the touch of a button.

The X4 range offers a choice of three turbocharged petrol and a pair of turbodiesel engines, ranging in output from 135kW to 225kW. All X4s get eight-speed Steptronic automatic gearboxes, but the xDrive35i is fitted with a Sports Auto version, promising quicker shifts, more responsive mapping, and manual override with shift paddles.

Also common to the entire X4 range is BMW’s xDrive all-wheel drive system, which seamlessly transfers power between the front and rear axles as conditions demand. It features Performance Control, which balances the power delivery between the left and right rear wheels to optimise grip and steering response.

The car I piloted through a landscape of of vivid green wheat fields in the Swartland was the range-topping X4 xDrive 35i M-Sport, which means the aluminium lump under the hood was a turbocharged 3.0-litre six-cylinder rated at 225kW and 400Nm.

Compared to the X3, the suspension is tauter, expressing the X4’s more dynamic intentions. And yet, ground clearance still exceeds 200mm, which means the X4 will clear more daunting obstacles than its city slicker styling suggests.

But let’s face it: the X4 is a highly unlikely candidate for all-terrain driving, and especially so in the case of this xDrive 35i. Despite the raised seating position, this X4 plays the performance car part with real aptitude.

BMW suggests a zero to 100km/h sprint time of 5.5 seconds, and on the move, that figure feels very much attainable. Top speed is 247km/h. However, it’s the way the X4 tackles the twisties that will raise eyebrows.

Remember, this is a 1.8-ton vehicle measuring 4.7m long and 1.9m wide, and offering a 204mm ground clearance. And yet, the dynamic experience is unexpectedly agile and road car-like. The view from the cockpit is commanding, and attacking the apexes of a series of corners proves just how wieldy and responsive the Beemer is.

Those big wheels and performance tyres create more road noise than you’d expect from a luxury machine, but the combined traction from the fat rubber and the all-wheel drive system makes the sacrifice well worth it.

Turn-in is precise, if not quite crisp, and there is little in the way of body roll, while the stance remains neutral, with the nose only threatening to plough wide into speed-scrubbing understeer when pushing too hard into the tight.

If anything, the elevated ride tends to understate actual progress, so that it’s easy to underestimate just how much momentum you’re carrying into a corner. To its credit, the X4 retains its poise even then, but generates the kind of g-forces you’d expect of a sports car.

While I was never convinced that the X6 would be a mainstream success, its global popularity has proven me wrong – which doesn’t say much for my ability to predict sales trends.

However, the X4 is a more convincing, more entertaining expression of the Sports Activity Coupé niche than its larger and heavier stablemate – which suggests that it should sell at least as well as its larger sibling.

It’s certainly more agile, more engaging, and ultimately more enjoyable. And with X4 prices starting in the mid-R600,000 bracket, this latest X-car from BMW is also more attainable, if not exactly cheap.

For now, the X4 has no direct rivals, even if Land Rover’s even more lifestyle-focused Evoque targets a similar motoring audience. But as auto makers continue to create new niche products in their efforts to woo buyers, don’t expect the X4’s expected success to go unnoticed. DM