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BIMMERPOST Review: M550d xDrive [M Performance Automobile] BIMMERPOST NEWS BIMMERPOST NEWS BIMMERPOST Review: M550d xDrive [M Performance Automobile] 15

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BMW M Performance - The Third Way



By Manfred Jerzembek

Photography by BMW



BMW is closing the gap between its most powerful regular cars and the M GmbH's ultra high-performance models. Under the "M Performance" moniker, a number of new vehicles will be released soon. Munich is starting out with several powerful diesel models, but gasoline-powered M Performance cars are sure to follow.



We had the chance to sample the M550d xDrive (official info thread) for an 85-mile drive, starting at the M GmbH's headquarters in Garching near Munich and leading to a nice, Bavarian lunch stop at Gut Sedlbrunn, north of Augsburg.



A first walk around the car reveals the subtle changes which set this M Performance model just slightly apart from the regular 5 series, while keeping a respectful distance to the M5. The M550d xDrive is equipped with the same aerodynamic kit and the 19-inch M wheels that are part of the M Sport package, but there are a few exclusive touches to this M Performance car. Instead of foglights, it's got a horizontal blade in the lower air intakes, painted "Ferric grey", and the outside mirrors are painted in the same color. And while the trapezoidal exhaust tips are identical to the 550i's, this is BMW's first diesel which doesn't sport round exhaust pipes. A discreet rear spoiler lip is standard. The overall appearance is far from ostentatious and fits the character of the car well.











Inside, we recognize many elements from the M Sport package, including the European-market "aluminum hexagon" trim, and the M Sport seats. Exclusive to the M550d xDrive are specific door sill panels, and a reshaped gear selector with an "M" logo. A push on the button starts the 3.0-liter turbodiesel, which emits a distant growl - and the unavoidable vibration of an oil-burner - at idle.



Stepping on the accelerator unleashes a remarkable 546 lb-ft of torque, which are available between 2000 and 3000 rpm; maximum power - 376hp - is reached between 4000 and 4400 rpm. The engine redlines at 5400rpm. BMW has achieved this power by installing three Borg Warner turbochargers - two small, variable turbine geometry high-pressure chargers, and one large low-pressure unit.









The intercooled system operates in a specific sequence: At low rpm, just one of the smaller turbos becomes active in order to optimize throttle response. From 1500 rpm up, the large turbo joins in and helps reach the torque maximum. Finally, from 2700 rpm onwards, the third turbocharger, mounted in a bypass tube, spools up and compresses the air before it reaches the larger, low-pressure turbo. Maximum boost pressure is 3.5 bar. The common-rail diesel injection system operates with a maximum 2200 bar of pressure, up from the 1800 bar which the twin-turbo 535d can reach. The 3.0-liter straight-six diesel engine received a significant redesign to cope with the massive power and torque.



Behind the wheel, seated firmly in the sports seats, we notice precious little of the complex turbo operation taking place under the hood. What we feel is an uninterrupted power trip: The M550d xDrive reaches 62mph in just 4.7 seconds, top speed is a governed 155mph. This car could go a lot faster, and you feel it, but the governor will remain in place "for the time being," says BMW. The engine's grumble is unusually sporty for a diesel - we have included a soundtrack -, but it does not come close to the silky, slightly nervous and altogether delightful frequencies emitted by BMW's straight-six gasoline engines. "The car is designed to offer forceful acceleration even when you are already travelling at high velocity," says Dr. Nikolai Ardey, head of BMW diesel engineering at Steyr, Austria. His credo: "maximum boost for maximum performance" - and it truly works on the road.









A ZF-sourced eight-speed automatic is standard. Eight speeds? Less could be more, but at least the shifts are seamless and unobtrusive. The slushbox remains discreetly in the background, and it's not as playful as the seven-speed dual-clutch transmission of the M5. Like its big brother, the M550d xDrive is equipped with hydraulic power steering - precise, nicely weighted, and far preferable to the electric power steering which comes standard on lesser 5 series models. The brakes are taken from the 550i, and the all-wheel drive system is calibrated to discourage understeering. But you can't help noticing this car's excessive weight: At 4,178 lbs, it is 220 lbs heavier even than the twin-turbo 535d xDrive, not a car known for its emphasis on weight reduction.



This M Performance sedan is resonably comfortable, despite the 245/35 front and 274/30 rear tires on 20-inch wheels which were fitted on our test car. BMW's chassis experts tell us that the Dunlop tires make for a better ride, but the Michelin tires which are alternatively offered are preferable if performance is your main focus.



One of the most impressive characteristics of the M550d xDrive is its efficiency: Despite its heft and its near-supercar performance, the car is rated at 37.3 mpg in the - admittedly optimistic - European cycle. In real life, you deserve congratulations if you get more than 30 mpg, but that's still a remarkable feat. There is an "Eco Pro" mode in the drive selector, which softens the car's responses, and a "brake energy recuperation" gauge on the dashboard. This car, after all, is supposed to be "socially acceptable" even in environmentally conscious Europe.











Will it be offered in the US, too? Sorry, no. The M Performance diesel - this engine is also offered in the X5 and X6 - is sold only in Europe, South Africa, and Australia. BMW explicitly rules out North America and Asia. But there will be other M Performance models with gasoline engines. At the Geneva auto show, BMW will show a near-production concept of a hatchback M135i, and it is strongly hinted that more cars will follow. In the future, a derivative like the Z4 sDrive 35is would surely be an M Performance model; there could be higher-powered 3 series models, and even a derivative of the 7 series is possible - not too soon, considering the success of the Audi S8 and the Mercedes-Benz S class AMG. There is justifiable hope to see a lot of M Performance models in the next few years - and while they are a significant step up from the regular BMW cars, the distance to the real M models will still be so great that there is little danger the Garching-designed icons will suffer any damage.







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