DRIVEN: Bentley Bentayga Diesel

MARBELLA, Spain – It’s a controversial thing, the Bentley Bentayga. But it sure has been selling well.

Yes, just a year after the very first example of the Bentayga rolled off the production line in Crewe, the British automaker is on track to produce as many as 5 500 of these hulking SUVs in 2016, exceeding initial forecasts by more than 50% as waiting lists grow by the day.

And, to add fuel to the fire sparked by its polarising styling and the very fact that it is, well, a Bentley SUV, the Bentayga can now be ordered with a diesel heart.

Diesel? In a Bentley? That’s a first, surely…

It certainly is. Not only is the Bentayga the brand’s first-ever SUV, it’s also the vehicle chosen to introduce its first-ever oil-burner. Indeed, this 4,0-litre V8 marks the debut of diesel in a Bentley almost 98 years after the company was established.

So, it’s taken quite some time. But what a triumph of engineering this powerplant is. With some 320 kW and a stonking 900 N.m (yes, a peak torque output to match the 447 kW W12-powered variant) on tap, Bentley bills the Bentayga Diesel as the world’s “fastest and most powerful luxury diesel SUV”. No small claim.

Hang on a second. Those figures sound strangely familiar…

They should. They’re shared with the Audi SQ7 (which is currently under consideration for introduction to South Africa in 2017), one of the Bentayga’s many platform-sharing Volkswagen Group siblings. The engine was apparently co-developed by the two brands, although we have a feeling Audi did much of the initial leg-work.

Still, Bentley has added its own engine and transmission calibration (including unique gear ratios), and as many as eight off-road modes (even if most of its customers won’t use a single one). The automaker furthermore completed its own thermal development and – as has long been a Bentley custom – not electronically limited its top speed (giving it a 20 km/h edge over the 250 km/h Audi). The British manufacturer even developed its own acoustic package for the Bentayga Diesel.

Acoustic package? So fake noise, then?

No, surprisingly not – you’ll find no aural trickery here, sir. Thanks to an exhaust system that places refinement above all else – as well as wads of highly effective sound-proofing and vibration-killing material – you’d be hard-pressed to tell you’re wafting along in a diesel, even under heavy throttle. Sure, some evidence of the oil-burner beneath the bonnet reaches the ears of those outside the vehicle, but it’s still all rather subtle.

So, tell me more about this ‘clever’ engine…

Well, as in the Audi, the 32-valve eight-pot features a pair of twin-scroll turbochargers as well as an electric supercharger. The latter draws power from a 48-volt system (rather than being driven by the engine), working in the first third of the power curve to provide boost at low engine speeds.

The result is that the mammoth maximum torque figure becomes fully available as early as 1 000 r/min, essentially eliminating turbo-lag and giving the first conventional turbocharger ample chance to come on song. Once the final blower comes to the party (and the electric compressor is disengaged), the engine is effectively bi-turbocharged, with torque tapering off only after 3 250 r/min.

Sounds terribly complicated. Does it work in the real world?

Indeed it does. Surfing that titanic wave of torque makes for rather easy driving, even if you’re pushing on a little (the slick eight-speed ZF gearbox helps here, too). And, as the driver, you’re never actually aware of all the under-bonnet sorcery, despite the system’s seemingly intricate nature.

Simply put, nail the throttle and off you go, revelling in the linear delivery of outwardly effortless oomph, which belies the fairly portly Bentayga’s 2 390 kg kerb weight and hustles it from standstill to 100 km/h in a mere 4,8 seconds (just seven-tenths tardier than the W12). Add permanent all-wheel drive and pleasingly accurate steering to the mix, and you have point-and-squirt luxury motoring at its very finest.

And it goes round corners, I take it?

It does. Somewhat better than expected, too. Look, there’s no hiding the Bentayga’s obvious weight through the bends, but it corners remarkably flat once the dial is turned to “Sport”, and grips with more enthusiasm than something this hefty should. And, perhaps best of all, it doesn’t sacrifice its absolutely superb ride quality in the process – although the breath-taking roads we sampled in southern Spain admittedly served up very little in the way of ride-testing imperfections.

It must also be pointed out that the vehicle we sampled was specified with the brand’s Dynamic Ride system – standard on the W12 but optional on the Diesel. This electric active roll control technology makes use of the 48-volt system to counteract lateral rolling forces when cornering, allowing the Bentayga to simultaneously tick the dynamic and comfort boxes.

So, how do I spot a diesel-powered Bentayga?

Well, Bentley’s designers have kindly handed this derivative a few distinguishing styling features, including a gloss black grille up front, distinctive “twin-quad” tailpipes round back and subtle “V8 Diesel” badging on the front doors. Other than that, it looks just like a W12.

And inside?

Business as usual in here, which means acres of sumptuous leather, fine craftsmanship and a general air of super-luxury. This diesel-powered model, incidentally, also introduces a new veneer – something that happens only once every few years at Bentley – called Liquid Amber.

Interesting. Well, just one question remains. This or the W12?

That’s not an easy one to answer. Traditionally, one might say the petrol-powered W12 is the one to have. But this (cheaper – although by exactly how much in SA has yet to be determined) Euro 6 diesel derivative offers a comparable level of effortless grunt, along with the sort of refinement that has until now been unheard of in the world of diesel.

Add to that a potential range of more than 1 000 km (even rich folk don’t enjoy filling up, after all) from the cleanest Bentley engine ever, and you have a compelling luxury SUV with superb grand touring abilities, a spot of off-roading talent and the usual lofty levels of comfort expected from the brand. And that gives us the distinct impression that the diesel model will end up at least matching or even outselling the W12 in the vast majority of markets in which it is offered.

But, perhaps most unexpectedly of all, it’s thanks to this absolute tour de force of a diesel heart, rather than in spite of it, that this thing still feels like a Bentley. Strange, but true…

Fast facts

Model: Bentley Bentayga Diesel
Price: TBA
Engine: 4,0-litre, V8 turbodiesel
Power: 320 kW @ 3 750-5 000 r/min
Torque: 900 Nm @ 1 000-3 250 r/min
0-100 km/h: 4,8 seconds
Top Speed: 270 km/h
Fuel Consumption: 7,9 L/100 km
CO2: 210 g/km
Transmission: eight-speed automatic
Maintenance Plan: TBA

Local introduction expected in mid-2017