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The M550d xDrive requires you to readjust any thoughts of traditional performance car values

Our Verdict

BMW M5
The latest BMW M5 gets twin-turbocharged V8 engine

The BMW M5 is crushingly capable, but some of the charm of old M5s is gone

23 February 2012

What is it?

Forget the sixth-generation M5 – the mighty BMW M550d xDrive is now the ultimate BMW 5-series model. At least it is in real world terms, on the sort of roads and in the changeable weather conditions we tend to encounter every day.

Spearheading a new range of so-called BMW M Performance models positioned and priced between the German car maker’s standard offerings and its more potent M division line-up , the rapid four-wheel drive diesel powered saloon establishes a lofty new standard of performance for oilburners: official figures put the M550d xDrive’s 0-62mph time at 4.7sec, standing kilometer (very much the new benchmark) at 23.7sec and a top speed at 155mph, even though it is clearly much higher without electronic regulation.

What's it like?

Granted, that’s not ultimately as fast as the new twin-turbocharged 4.4-litre V8 petrol engine powered M5 in a straight line, but it is the way it achieves these figures with such pervading potency at only moderate engine revs that makes the M550d xDrive so utterly appealing. It is a car that always feels like it has more in store, more to offer – even when scything along at triple digit speeds out on the fast lane of an unrestricted German autobahn. That, and the fact it is claimed to return 44.8mpg on the combined consumption cycle. Talk about having your cake and eating it, too.

Taking pride of place under the bonnet of the M division fettled four-door is the N57S, as BMW M division insiders like to refer to it. The highly complex and expensive to produce tri-turbocharged 3.0-litre in-line six-cylinder diesel engine – also destined for the upcoming X5 M50d and X6 M50d – provides BMW’s first dedicated performance diesel with the sort of instant-on performance and inherent entertainment value you usually only ever encounter from a high capacity petrol powerplant.

The aluminium block engine is a true technological tour de force, but despite BMW’s best efforts it still weighs 24kg more than the twin-turbocharged 3.0-litre unit it is based on. This places even greater weight over the front axle than the 535d – a car which it pips in overall output by 81bhp and 103lb ft at 376bhp and 545lb ft – the latter developed between 2000 and 3000rpm. And I never remember thinking the 535d lacks for punch.

What these bald figures fail to convey is the omnipresent energy. There’s no off-boost lethargy or waiting for it to come on song as engine speed builds. With the latest in high pressure, piezo valve guided direct injection together with a small, low interia turbocharger working in concert with a larger unit at low engine speeds to enhance the induction process, it delivers enormous shove and tremendous flexibility, and that’s just in the first couple of thousand revs.

Above 2700rpm, a second small turbocharger is engaged, providing additional boost pressure (up a maximum of 3.5 bar) and truly monumental in-gear thrust – the kind to make even the M5 feel, dare I say, a tad weak by way of direct comparison. Despite the M550d xDrive’s 1895kg kerb weight, it is heroically, epically quick.

Diesel engines aren’t supposed to respond to throttle inputs like this. At any revs, in any gear, the M550d xDrive simply flies. Pegged hard, its accelerative nature is nothing less than brutal. Nor are oilburners meant to accept revs with such unbridled enthusiasm. The new BMW engine feels totally at home operating beyond 4000rpm. In fact, it encourages you to. Peak revs are limited to 5500rpm.

What’s more it sounds terrific. Unlike the M5, which receives a synthetic soundtrack, the M550d xDrive’s aural traits are genuine – although in a process that is gaining popularity right across the automotive spectrum, BMW does rely on the speakers to enhance their effect. The combination of engine and exhaust sounds is not unlike the original Audi quattro, with a deep warble at low revs and a wonderfully exuberant baritone wail up high.

For all its undoubted enthusiasm, epical thrust and aural delights, though, it’s easy to overlook perhaps the M550d xDrive’s most convincing traits – it’s superbly refined nature, relative economy and crushing long distance qualities. Mated to an upgraded version of BMW’s superb eight-speed automatic gearbox, the engine is not totally free of vibration but is smoother than any other high performance oilburner throughout its entire rev range, returns real world consumption not too far from BMW’s own claims and requires just 3000rpm at a heady 120mph cruise.

It’s big and heavy, but with the latest version of BMW’s four-wheel drive xDrive system apportioning drive to each corner it handles well, even in tricky weather conditions. It can’t quite match the M5 for overall dynamic ability: the electro-mechanical steering system lacks for consistent weighting and the ride is a little brittle (even in comfort mode) on certain surfaces. But with one determined stab of the throttle any deficiency is forgotten.

Should I buy one?

The M550d xDrive requires you to readjust any thoughts of traditional performance car values.

Don’t get too worked up, though. Like all existing four-wheel drive versions of the 3-, 5- and 7-series, the M550d xDrive is not planned to be produced in right hand drive. There is, however, a slim chance that BMW will place its brilliant new diesel engine in a rear wheel drive version of the M550d. Until then, the M5 remains the king, here in the UK at least.

BMW M550d xDrive saloon

Price: n/a; Top speed: 155mph (limited); 0-62mph: 4.7sec; Economy: 44.8mpg (combined); CO2: 165g/km; Weight: 1895kg; Engine: 6 cyls in-line, 2993cc, tri-turbo diesel; Installation: Front, longitudinal, AWD; Power: 376bhp at 4000rpm; Torque: 545lb ft at 2000rpm; Gearbox: eight-speed automatic

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Comments
40

23 February 2012

[quote Autocar]

What is it?


Forget the sixth-generation M5 – the mighty BMW M550d xDrive is now the ultimate BMW 5-series model. At least it is in real world terms, on the sort of roads and in the changeable weather conditions we tend to encounter every day.



Spearheading a new range of so-called BMW M Performance models positioned and priced between the German car maker’s standard offerings and its more potent M division line-up , the rapid four-wheel drive diesel powered saloon establish...Read the full article

[/quote] Could be tempted if i could afford it,but i can't,so there you go,and yes, i'm a petrol driver.

Peter Cavellini.

23 February 2012

Those figures are crazy!

I'd love to see this engine in the new 3-Series, although it would make the M3 kind of obsolete. And it probably wouldn't fit.

23 February 2012

Not bad!

So are we at long last getting a 4WD 5-series in the Yoo Kay then?

DKW

23 February 2012

[quote Autocar]the M550d xDrive’s aural traits are genuine – although in a process that is gaining popularity right across the automotive spectrum, BMW does rely on the speakers to enhance their effect[/quote] So genuine and ungenuine ? Hope you can switch off the speakers, I like a bit of peace and quiet.

DKW

23 February 2012

[quote Overdrive]So are we at long last getting a 4WD 5-series in the Yoo Kay then?[/quote] Don't think so. But contrary to what is implied in the article, I think we will nevertheless get this engine here - in the X6 and possibly the X5.

23 February 2012

In context the standing kilometre time for an E92 M3 was about 24 seconds...

23 February 2012

[quote DKW] I think we will nevertheless get this engine here - in the X6 and possibly the X5[/quote]

I am intrigued as to how this engine will perform in them.

23 February 2012

Impressive car and as the report says, probably a better real world car than the M5 but I can't help but be scared witless by the prospect of having to maintain it four years down the line!

 

 

It's all about the twisties........

23 February 2012

Just think what Alpina could do with this.

507

23 February 2012

Interesting to hear if anyone can think of a competitor? And yes, you can turn the sound off by the. Up to 50mph it leaves an M5 behind as it will indeed do on any wet, poor surface! The engine will indeed come in most models, nearest in line are the 7, 6 and 3-series followed by the 4-series and the X4. There is even more and more talk about an M150d xDrive in both 5dr (F20) and 3-dr (F21) versions. The 2-series is another likely candidate.

If you look at the induction side you can clearly see why this engine will win BMW awards!

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