BMW M550d xDrive- the ultimate diesel?


Top Post Dawg
Sep 5, 2001
san antonio & austin
formerly: 2001 Golf GL, '97 Passat (RIP) '98 NB, '05 B5 sedan
I rode in a 550i xDrive while in Germany last month and was blown away on how it cruised the autobahn. The pull from 120mph was fantastic! :D. I can't imagine how much better the M550d would be.

Unfortunately, there are no plans to bring it to N America.

In the 1980’s BMW offered some of their first diesels to US consumers. To say they were not well received is an understatement.

To some, diesels still remain dirty, noisy, less refined and offer little in terms of driving fun. However, this is partly based on their living in the past.
Technology has moved on since the diesel powered cars of the 1980′s. Just like cell phones are no longer as big or as heavy as a brick, computer screens are not monochrome, diesels are not just for tractors. The M550d xDrive is being touted as the best of the best diesels currently on the market. But how does BMW’s triple turbo six cylinder really perform? We criss-crossed the Alps to find out for ourselves.

M GmbH, BMW’s motorsports associated tuning arm, more commonly referred to as simply “M”, has over 400 engineers developing products that are cutting edge for efficiency and performance. Not everyone wants the typical M offering like the M5 that could easily be used as a daily driver and a track machine though. Some just want a more driver oriented car. Fear not, M is changing its ways.

The M550d introduces an entirely different category of M tuned products; the M Performance Automobiles line. These new offerings are directed towards consumers that would like more performance but do not want to sacrifice things like all-wheel-drive or for those Euro-centric, diesel. This new line will be exclusive to Europe for the near future but will enter the US in gas powered offerings in the not so distant future.

The M550d xDrive is ground breaking for the M division. It is their first crack at diesels and an all wheel drive sedan. They are pushing boundaries just as they did with the original 1986 M535i, the model that began their reign as the producers of the best high performance sedans on the planet.

With 381 hp and 585 lb-ft of neck snapping torque the 3 liter inline six is anything but boring. Smashing the pedal and having the seat back and lumbar set just right may even yield a free Chiropractic adjustment. Code named N57, it features the first production tri-turbo engine with high pressure direct injection. It utilizes everything possible from the M bag of tricks to produce power while being efficient and easy to drive such as variable vane as sequential turbocharging.

What BMW M has created is an engine that redefines the entire diesel category; not bad for a first try. It is responsive, smooth revving and sounds- unbelievable. This engine is the reason BMW announced several years ago that they would be ceasing their V8 diesel development. Somehow this diesel sounds throaty and petrol like, there is no “tuck-tuck-tuck” tractor sound which may be its biggest surprise. The redline sneaks in at a level unknown to most diesels, 5400 rpms. The power band is impressive and there is little in the way of turbo lag once moving. Most would be hard pressed to know it was a diesel if solely based on the character and performance of the engine. This point was driven home at the first fuel fill-up, a passenger was worried that we were filling up with the wrong fuel because there was no way the car they had been rocketing in comfort was a diesel.
Thanks to xDrive all that power is put to use and launches the mass of the heavy F10 5er in the oh-so important dash to 60 in what BMW’s notoriously conservative times claims to be 4.7 seconds. In real life it’s much quicker- ask the fellow in the E92 M3 that volunteered to see who’s ride was quicker and came out the loser.

The xDrive system also creates a feeling of more stability at high speeds, something welcomed in a ‘Bahn burner of such mass. xDrive is at home on the Alpine passes in any condition- rumor is that this whole M Diesel idea came about because one executive wanted to get to Kitzbühl to take advantage of some fresh powder but wanted to get there with the most performance and efficiency but there wasn’t anything outside of an X5 M to fit his needs. The lightbulb came on and now there are M diesels.

The fantastic ZF 8HP eight speed automatic transmission (featuring auto stop/start) is a perfect mate by providing quick shifts at the right time. Performance is not the only area in which the M550d excels, it is efficient to boot. Given our propensity to have a lead foot the 32.5 (calculated) mpg this beast yielded over the course of two weeks in the Austrian and German Alps was nothing less than miraculous. Simply put, this sedan may be the perfect mix of frugality and performance. It rewards at the pump and doesn’t take away from the fun.

The fun factor was high thanks in part to the twisty Alpine passes and back roads the less than stellar iDrive navigation algorithms chose as the route. At some points we joked that the nav was enjoying the ride because it seemed to never go directly from point A to B, and yes the right boxes were checked for route planning! The suspension was firm in “sport” mode and supple in “comfort” thanks to M improved hardware and the now customary console mounted rocker switch. The M tuned hydraulic steering reintroduces the 5 series to road “feel”, something the standard model with Electric Power Steering is not known for. Compared to the rest of the 5 Series lineup the M Performance suspension is firmer and lower. Another exciting development for the M550d is that it is the first BMW sedan equipped with a lowered suspension and xDrive all wheel drive, hopefully this begins to spread!

If there is a weak spot with this M product, it’s the brakes. A car with all this get up and go needs the ability to stop just as well and it just doesn’t. The floating calipers fore and aft stop the heft well enough but when you need a bit more brake it just is not there. High speed cruising on the German autobahn requires confidence in one’s abilities and to trust the vehicle you are in, that is easy to do with the M550d except with the braking; thinking about extra distance is a necessity. Maybe it has less to do with the brakes than the fact the 5 Series is porky and weighs a bit more than it should, either way it takes longer to come down from high speed than we’d like or expect. These are the same brakes as what the US gets in the 550i and we would have anticipated M doing a bit more with the binders.

Currently, there has been no indication that the M550d will make it stateside, which is sad. Being EU Bin 6 for emissions should make it 50 state legal without any need for further modifications but we are not the EPA or CARB members, so maybe we’re just dreaming there. In theory BMWNA could bring it over with no added development, sure its pricy but coming in just below the full on M5 but as they say, you get what you pay for.

That said, what quite possibly may be BMW’s best all around sedan more than likely will be constrained to the suffering EU market, its a big ticket item and sales will be slow at best. We’d take the M550d as a daily driver over any hybrid, and if we were smart rather than passionate we’d take this over the M5 as well- with a set of real brakes of course.