Diesel models are currently having a hard tim. Sales numbers are declining all over the world and its reputation has suffered a lot from illegal software manipulation by leading automotive companies. But since the diesel isn’t simply disappearing from one day to the other, car manufacturers still offer a variety of diesel-powered cars in their line-up. One of the most impressive diesel cars in BMW’s line-up is the all-new BMW M550d xDrive, available as a sedan or a sports wagon (or Touring according to BMW language). While we tested already the BMW M550i back in April 2017, we were now eager to have a look at its diesel-powered sibling.

Like the BMW M550i, the M550d is part of the BMW M Performance Automobiles lineup. The new product category celebrated its debut at the 2012 Geneva Motor Show and closed the gap between the hardcore M cars and the standard model line. While the first generation of the M550d was based on the F10 and powered by a set of three turbochargers, the all-new generation makes use of the new G30 platform and a set of four turbochargers.

Our short-term test car featured the BMW Individual color Rhodonite Silver. The optional metallic painting combines the brighter color tones of silver (if the sun is shining onto the color) and the darker tones of grey in overcast weather. The elegant paint makes the M550d look even more inconspicuously, and if the car wouldn’t feature the M550d badge on the rear and the 20-inch double spoke wheels 668, you could very well think we got a BMW 520d Touring for the weekend. However, when opening the driver’s door, the illuminated door sills remind you immediately that you are getting behind the wheel of the M550d.

Before I continue with the cars technology I need to share my enthusiasm about the exterior design of the Touring. The long roofline and the bright D-pillar with the Hofmeisterknick create an unmistakable sporty appearance, and in addition, the M sport suspension lowers the cars body by 10 millimeters and the M-specific exterior modifications differentiate the M550d from the standard model. However, you have to take a close look to spot the differences. Simply watch out for exterior details painted in Cerium Grey color. If you spot a 5 Series with grey kidney frame grilles and mirror caps painted in grey, you might have found an M550d (or M550i).

Engine and Technology

The BMW quad-turbo diesel engine, internally code-named B57, is a breathtaking masterpiece of engine technology. Never before did I experience such a massive but yet consistent power delivery in a car. Words are barely able to describe this performance. At all moments in time, the M550d created a feeling of clear superiority. Whenever I had to accelerate for a quick sprint, the massive power was there. The only disappointment I had was the missing emotional component. The sound of the diesel engine was barely noticeable behind the wheel. And even when I was able to spot some tones, they didn’t create a lot excitement.

Looking at the B57 diesel engine and its performance, the M550d offers already more than 331 lb-ft of torque available at 1,100 rpm. Peak torque of 560 lb-ft is available between 2,000 rpm and 3,000 rpm. The engines power is created by a sophisticated combination of multi-stage turbocharging and the latest common rail diesel technology. The set of four turbocharges is designed to work on two levels. One is the high-pressure stage, the other one is the low-pressure stage. The two low-pressure turbochargers and one of the two high-pressure chargers are constantly active, while the second high-pressure charger is only added at 2,500 rpm and more. All in all, the inline 6-cylinder diesel engine offers a maximum power output of 400 hp at 4,400 rpm and accelerates the Touring from 0 – 60 mph in just 4.6 seconds.

But the enormous power isn’t the only advantage the diesel-powered engine is good for. The moderate fuel consumption of the M550d makes the gar an incredible good long-distance cruiser. While BMW promises an average fuel economy of only 38 mpg, I managed to only get 28 mpg on my weekend drive. Although the result isn’t anywhere close to the official numbers, I think it’s still acceptable. Especially if you keep in mind, that the M550d (4.6 seconds to 60 mph) is as fast as the old M5 F10 generation (4.7 seconds to 60 mph).

The M550d distributes its power to all four wheels via the standard 8-speed Steptronic sports transmission. A manual transmission isn’t offered. The BMW xDrive system comes standard as well and is precisely modified to match the M Performance character of the car. The system is still rear-wheel drive oriented and capable to transfer the power onto the street.

Driving Experience

In order to take a close look on the M550d and to experience its performance, we took our short-term test car out for a drive in the Bavarian and Austrian mountains near, Berchtesgaden and Salzburg. The area, which is typically known for its great mountain panorama, offers a variety of alpine passes with curvy roads and stunning views.

Once you get behind the wheel of the M550d, you notice the charm and practicality of the current BMW 5 Series generation. Every button and control unit is exactly where you expect it to be. Only little details remind you that you are driving an M performance car, such as the M550d lettering in the instrument cluster.

Our first destination on the way Austria was a scenic mountain road near Berchtesgaden, the Rossfeldstraße. It has a lot of twisty curves and, thanks to rainy weather, I was able to experience how precise the xDrive system is. In the blink of an eye (or even faster), it distributed the power exactly where it was needed. The M550d felt perfectly stable and stuck to the road in every corner and I was amazed how easy but yet precisely it was to drive the M550d Touring. The feedback of the steering was also extremely precise and felt perfectly consistent with the car’s chassis. Most of this praise goes out to the BMW’s Integral Active Steering, which comes standard for the M550d. The system uses a co-steering of the rear wheels and increases therefore ride stability and maneuverability.

Infotainment and Safety Features

While I was completely fascinated by the performance of the M550d, there was a lot more to the car. The smartphone-like key of the car was just the beginning. Although I found the Display Key pretty fancy on the first day, it quickly become obvious how large it is, especially when you need to carry it in the same pocket with other items.

The display key is only providing basic data of the car, which the BMW Connected App is able to provide as well. Except for the Remote Parking feature. That’s the feature you need the display key for.  Speaking of the remote parking feature, I found myself to be very cautious with it and SSnce I have never operated a car remotely before, I had plenty respect for it. Consequently, I tried it for the first time on a closed road with plenty of space in front and behind the car. But since everything worked fine, I quickly became familiar with it.

Another feature I didn’t need to become familiar with is BMW’s Connected Drive package. The latest generation has brought the connectivity between the driver and the car to a new level. Never before did I interact so easily with a car. My smartphone was connected in the blink of an eye and entering a navigation address didn’t take much longer. It felt as I would be able to operate the system even with closed eyes. But today, there is actually much more to the Connected Drive package than only navigation services and smartphone connectivity. By using the BMW Connected App I was able to remotely view the surroundings of the car while enjoying my dinner at the hotel.

Next to BMW’s award winning Connected Drive package, the M550d came with all state of the art safety features. While I am not the biggest fan of all assistant features of today’s cars, I was eager to experience the Lane Keeping Assistant and how it would work in combination with the radar-based Active Cruise Control. Would it relief me from boring stop and go traffic on the highway or would it create even more stress behind the wheel?  My conclusion is a kind of a mixed picture. On the one hand, I was happy to see that the system worked properly in stop and go traffic on the Autobahn at low speeds. On the other hand, I can’t truly recommend the system at higher speeds, especially if the lane markings on the road are subject to disappear from time to time. In these situations the system will be deactivated and alerts the driver to take over the steering wheel. You better be focused at this moment when the alarm bell rings.

Should I Buy One?

While I was taking photos of the car at the BMW Welt, a bus of Asian tourists stopped at the Welt and two of them were immediately attracted to the M550d. After kindly asking, both started to take photos of the car and couldn’t get away from it for a couple of minutes. The same accounts for me. I was fascinated every second of the weekend by the M550d. And this feeling still exists while typing these words. I am caught by the pure performance of the diesel engine and its enormous torque, while averaging a decent fuel economy at the same time. The BMW M550d offers the acceleration power of the former BMW M5 F10 and combines it with the fuel economy of a BMW 530d. In addition, the everyday practicality isn’t lost and makes the M550d suitable for every day to day challenge.