BMW lands world's most powerful diesel six

The world’s most powerful six-cylinder diesel engine is now available in Australia, underneath the bluff snout of BMW’s facelifted X6 ‘SUV-coupe’ and the X5 M50d.

Priced at a neat $157,000 plus on-road costs – some $33,900 more affordable than the range-topping twin-turbo petrol V8-powered X6 M - the new X6 M50d’s tri-turbo diesel engine slams out no less than 280kW of power and 740Nm of torque, making it the world’s most powerful volume-produced six-cylinder diesel in a passenger car.

The same outrageous new diesel engine also powers BMW’s new X5 M50d ($147,000 — $11,200 less than the X5 M), which goes on sale here in two months, and between them the first two M Performance Automobiles models to arrive in Australia have already attracted more than 70 Australian buyers.

While the high-riding X6 SUV has been a hit globally, exceeding BMW’s expectations by attracting about 150,000 sales – as well as spurring the company to develop the upcoming 3 Series-based X4 and Audi to develop its forthcoming Q6 – it has not achieved the same success here.

BMW Australia has sold around 1900 examples of the X6 since 2008, but expects the facelifted model – including the new M50d – and the addition of a three-seat rear bench seat (previously a $700 option) and internet access ($200) as standard to increase sales.

“It’s no secret that Australians haven’t embraced the X6 like people have everywhere else in the world – especially in the US, Russia and Middle East – but on the other hand the X5 attracts disproportionately high sales here,” said BMW Group Australia spokesman Piers Scott.

“We’re confident X6 M50d will attract new customers to the X6 by opening up a new category of performance vehicles. The risk of sales cannibalisation of the X6 M is minimal, because the M50d slots into the void between it and the mainstream models.”

As we’ve reported, pricing for the upgraded X6 is up by $1000 across the range, while the range-topping X6 M is $5500 more expensive than before at $190,900.

There are no mechanical changes for the midlife X6 makeover, except for the addition of the tri-turbo diesel engine in the M50d, which also represents BMW Australia’s inaugural BMW M Performance model.

Based on the single-turbo 3.0-litre inline six-cylinder N57 diesel engine fitted across the BMW range (and the twin-turbo engine in the 535d and X6 40d), the M50d features a large, low-pressure turbo bookended by two smaller, high-pressure turbos (with up to three bar of boost), the first of which force feeds the engine alone at up to 1700rpm, before feeding the large turbo in the midrange, and the second of which continues to spool up all the way the engine’s high 5250rpm cut-out.

The result is no less than 280kW at 4000-4400rpm and some 740Nm of torque at 2000-3000rpm, claimed 0-100km/h acceleration in a sportscar-like 5.3 seconds and official combined fuel consumption of just 7.7L/100km.

The same engine in the all-wheel drive M550d all, which is not produced in right-hand drive guise and therefore unavailable in Australia, is capable of hitting 100km/h in a staggering 4.7 seconds – the same as the previous E60 M5 V10 super sedan and just four-tenths slower than the latest twin-turbo V8 petrol-powered M5.

That makes the X6 M50d quicker than Audi’s bullocking 6.0-litre V12 diesel-powered Q7, which produces 386kW and some 1000Nm and sprints to 100km/h in 5.5 seconds, and the 250kW/760Nm Q7 4.2 TDI (0-100km/h in 6.4 seconds).

All facelifted E72-series X6s come with a new front bumper with redesigned kidney grille and higher/wider foglights, new L-shaped tail-lights and the option of adaptive LED headlights ($3400), while the M50d comes standard with the US market X6 hybrid’s ‘Powerdome’ bonnet, which costs $1100 extra on all other models.

The usual host of BMW options is available across the range, including metallic paint ($2000), an electric glass sunroof ($3500), a selection of 19- and 20-inch alloy wheels costing up to $4800, self-levelling suspension including rear air suspension ($2200 – standard on 50i and M50d), steering wheel heating ($500), an alarm ($1050), auto soft-close doors ($900), four-zone climate-control ($3200), an active driver’s seat ($900), front seat ventilation ($1500), lane departure warning system ($1400), active cruise control ($4700), rear DVD system ($4400), TV ($2800) and anthracite headlining ($700).

Three new exterior paint colours are available for the 2012 X6 - Glacier silver, Midnight blue and Marakesh brown – along with two new upholsteries: Ivory Nappa and Vermillion red.

Specific M equipment for the M50d includes an aggressive bodykit that swaps front foglights for massive air intakes, M Servotronic steering, M-tuned Adaptive drive active rollbars, M-tuned front springs and dampers, revised elastokinematics, 20-inch 435 M-style double-spoke alloys with 315/35 R20 run-flat tyres, BMW Individual High-Gloss Shadow Line exterior trim, an M gearshifter, Ferric Grey wing mirror caps, a pair of black twin oval exhaust outlets on either side, M door sills, Aluminium Shadow Brushed interior trim, Nappa alcantara/leather trim with M badging, a 16-speaker 600-Watt surround sound system,   

Opening the fresh X6 range – which comes with an eight-speed auto as standard in all models - is the xDrive 30d, which comes with a 180kW/540Nm 3.0-litre turbo-diesel inline six, consumes 7.4L/100km, accelerates to 100km/h in 7.5 seconds and costs $110,900.

Next up is the xDrive35i, which is powered by a 225kW/400Nm 3.0-litre petrol engine, consumes 10.1L/100km, sprints to 100km/h in 6.7 seconds and costs $121,000.

Then there’s the $127,400 xDrive 40d, powered by a 225kW/600Nm twin-turbo diesel six that consumes 7.5L/100km and sprints to 100km/h in 6.5 seconds, and the 300kW/600Nm 4.4-litre twin-turbo petrol V8-powered xDrive 50i, which consumes 12.5L/100km and can hit 100km/h in 5.4 seconds – one-tenth slower than the M50d, which in turn is six-tenths slower than the X6 M.

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