GEORGE, Western Cape – Four. That's how many turbochargers BMW has strapped to the 3,0-litre straight-six diesel unit sited over the front axle of the M50d, the derivative that plays the role of flagship in the new, fourth-generation X5 range (ahead of the inevitable launch of the as-yet-unrevealed, full-fat X5 M, that is).

Overkill? Well, considering the M50d’s predecessor was a veritable sledgehammer despite employing one fewer turbo, the logical answer would be a resounding “yes”. But logic heads swiftly out the window when we’re talking about hefty diesel-powered SUVs capable of shaming sportscars from just a few years back (particularly in a straight line).

Yes, despite being crammed full of luxury kit – some of it standard and some cherry-picked from a varied list of options – and tipping the scales at a considerable 2,3 tonnes, the 294 kW M50d will quite happily catapult itself down your favourite strip of tarmac at quite a rate of knots, feeling just as rapid as its claimed 5,2-second 0-100 km/h sprint time might suggest.

Still, it’s the in-gear acceleration that’s most impressive here, with the eight-speed automatic transmission – that familiar, slick-shifting unit from the studious, cog-tinkering folks over at ZF Friedrichshafen – neatly keeping the inline-six operating within its meaty torque band, lending the driver’s right foot access to the full spread of 760 N.m (up from 740 N.m) more often than not. In short, delivery of the all-wheel-drive M50d’s considerable grunt is hair-raisingly linear (and the synthesised grumble in the sportiest of settings strangely addictive).

Diesel only ... for now

Interestingly, while the likes of the third-generation Porsche Cayenne have seemingly shunned diesel, the local BMW X5 line-up – admittedly comprising just two derivatives at launch – is powered exclusively by the stuff (the other variant being the 195 kW/620 N.m xDrive30d, which uses the same unit but fitted with a single turbocharger). That means – initially, at least – we won’t see the 4,4-litre V8 xDrive50i nor the 3,0-litre inline-six xDrive40i on local roads (BMW SA admits it could introduce petrol power in 2019, while adding that the plug-in hybrid xDrive45e is also under review).

So, besides the M50d gaining yet another turbo and even more go-forward grunt, what else has changed with the ushering in of this new iteration? Well, the Spartanburg-built, G05-generation X5 has grown considerably compared with its forebear, with some 42 mm added between its axles. Overall, vehicle length increases 36 mm to 4 922 mm, while an additional 66 mm of width and 19 mm of height afford the new model yet more cabin space.

New-look interior

The luggage compartment, meanwhile, now holds a claimed 645 litres, with utility space pegged at a useful 1 860 litres. BMW furthermore offers an optional R25 100 third row of seats for two additional passengers (a stance Mercedes-Benz will take with the upcoming version of its GLE, too), while a neat electronically operated two-section tailgate ships standard.

The most obvious change, however, is found towards the front of the cabin, where the facia has been completely overhauled. A new, highly configurable 12,3-inch display takes pride of place in the centre – running the latest, largely intuitive BMW Operating System 7.0 that we’ll soon see in the likes of the upcoming X7, 8 Series (both coupé and convertible) and Z4 roadster – while the driver sits ahead of a fully digital instrument cluster of the same size. Perceived quality, too, has been noticeably improved.

While the local launch included plenty of gravel-road jaunts in the xDrive30d derivative – in this instance fitted with optional off-road rubber that did an outstanding job of cushioning the blow each time we braced for impact with one of myriad rain-filled ruts on the sometimes rocky Prince Alfred's Pass, while hardly adding any road-roar on tarmac – all of our time with the M50d was spent on the black stuff.

Striking a balance

Though not quite as forgiving over road scars as that xDrive30d on its General Grabber AT3 tyres (in 275/45 R20 XL size and costing close to R72 000 extra), the M50d nevertheless strikes a compelling balance between comfort and dynamic ability. Despite employing the standard adaptive M suspension set-up (rather than the optional two-axle air suspension arrangement) and running on optional 22-inch alloys wrapped in 275/35 R22 front and 315/30 R22 rear run-flats, our test unit delivered an outstanding primary ride.

The X5 has long been one of the better-to-drive large SUVs and its latest CLAR underpinnings see it take things a step further. Still, while the new model is a touch sharper to drive than its already talented (for a hulking SUV, anyway) predecessor – largely resisting body roll and serving up huge grip even in the damp conditions we experienced on the launch – the new Cayenne is still a nose ahead in terms of on-road talent. But only just.

Priced at R1 502 581, the M50d is better equipped than one might assume, boasting items such as an “M” aerodynamic body kit, adaptive LED headlamps, a panoramic glass sunroof, four-zone climate control, M Sport brakes, a head-up display, gesture control and an M Sport exhaust system as standard. One of the most interesting of the numerous options is the R59 250 off-road package, which adds features such as underbody protection, the aforementioned air suspension (which is also offered as a standalone feature) and four additional drive modes. In addition, BMW SA says various M Performance parts will be available to order from the first quarter of 2019.

Battle royale looming?

While the eminently capable xDrive30d is probably all you’ll ever need (and will likely prove the more popular of the pair), the M50d is nevertheless a tempting alternative for those who crave serious oil-burning grunt. Both derivatives, though, display a broader spread of talents than before, including the ability to tackle seriously nasty gravel stretches provided the right options boxes are ticked.

With improved refinement levels, a flashier (plus more spacious) cabin and added on-board technology, the fourth-generation X5 has stepped confidently into the ring to face a host of talented rivals, with the latest Cayenne and soon-to-arrive GLE chief among them. So, just one question remains: comparative test, anyone?