BMW is launch its 5-Series M Performance models with the new diesel-powered M550d xDrive. Available in both sedan and the more practical Touring body styles, the M550d comes with standard rear-biased all-wheel drive, but it’s what lies under the hood that makes this 5er special.

Improving upon the previous M550d that had a tri-turbocharged 3.0-liter straight-six, BMW’s engineers added a fourth turbo to create the world’s most powerful six-cylinder diesel unit.


The two low pressure turbochargers that are new and replace the previous large-sized third turbocharger, are permanently powered during travel. The second high-pressure turbocharger kicks in at engine speeds of over 2,500 rpm. BMW says that at high load requirement from idling, the two low-pressure turbochargers are briefly circumvented by means of a flap control system to build up boost pressure even faster.

Retaining the same displacement as before, the quad-turbo’d lump has an output of 400 PS at 4,400 rpm, matching the E39 M5’s V8, but more importantly, 760 Nm of torque delivered from just 2,000 rpm, which is more than the outgoing M5 (680 Nm). Compared to the older M550d, that’s an increase of 19 hp and 20 Nm respectively. 


Power is transferred through a standard, M Performance-tuned 8-speed automatic transmission, with the M550d xDrive sedan accelerating from 0 to 100 km/h in 4.4 seconds and the Touring in 4.6 seconds. Both have an electronically limited top speed of 250 km/h. 

Naturally, it wins hands down when it comes to fuel consumption with BMW quoting an average of 5.9 l/100 km (39.9 mpg US / 47.9 mpg UK) with CO2 emissions of 154 g/km for the sedan and 6.2 l/100km (37.9 mpg US / 45.6 mpg UK) with 163 g/km for the Touring on the European driving cycle.


The diesel gains an M Sport suspension that lowers the body by 10 mm, with an adaptive M Suspension Professional featuring Dynamic Damper Control offered as an option. The M550d also gets what BMW calls an Integral Active Steering with a variable rack-and-pinion ratio.

The M550d features an M styling treatment with specific bumpers, the rear with a diffuser, side sills, blue brake calipers and a boot spoiler for the saloon. Cerium grey has been used on trim elements including the kidney grilles, door mirrors as well as on the standard 19-inch wheels shod in 245/40 R19 tires front and 275/35 R19 rear. If you want to go bigger, 20-inch wheels are offered as an option.


Inside, beyond the illuminated sill trims with an ‘M550d’ inscription, the front passengers get contoured sport seats, while the cabin has been dressed in swaths of leather, Alcantara and aluminum trims. The M-specific steering wheel with shift paddles, pedals, and instrument display round out the upgrades over the regular 5.