BMW M550d, X5 M50d and X6 M50d, All Powered by a Tri-Turbo Diesel

The new models are the M550d xDrive sedan, M550d xDrive Touring, X5 M50d and X6 M50d, and as their names suggest, they're all powered by the same diesel engine and feature the Bavarian firm's xDrive all-wheel drive system.

And before you get your hopes high, we'd better tell you that none of them are planned for the US market.

BMW's M Performance Automobiles sub-brand was created to offer a diverse lineup of models with a wide choice of engines including diesels not only to compete with Audi's S range, but as we reckon, also to avoid further dilution of the M division.

The four introductory models debut a new 3.0-liter inline-six diesel with three-turbochargers delivering 381-horsepower and a whopping 740Nm (546 lb-ft) of peak torque, all of which the driver will find on tap as low down as 2,000 rpm.

This is the first time that a BMW engine employs the use of three turbochargers. The system comprises two comparatively small turbochargers and one large turbo, which join forces to deliver the amount of power required by the driver.

BMW has also fitted all models with a system that imitates the engine sound in the interior through the audio system.

"The system’s digital signal processing technology exchanges data directly with the engine management, allowing it to base its precise transmission of the engine’s timbre on the revs at any one time, the amount of torque being produced and the car’s speed over the road," says BMW.

An eight-speed Sports automatic gearbox and BMW's all-wheel-drive system, tuned to suit each individual model, transfer power to the road.

In terms of performance, the M550d xDrive sedan is the fastest hitting 100km/h (62mph) from standstill in 4.7 seconds while consuming 6.3lt/100km on average (37.3mpg US or 44.8mpg UK). Note that the fuel consumptions listed in the chart below are in Imperial mpg (aka UK) and not U.S. mpg figures.

All four models benefit from modifications to the chassis components, including M-specific tuning of the suspension, bodyshell mounting, engine and transmission mounting, springs and dampers, all standard and optional chassis control systems, and the Servotronic mapping for the hydraulic steering.

In addition, the 5-Series based models ride on 19-inch wheels, while the X5 and X6 (seen here in its facelifted form, more on that later) on 20-inch alloys.

Each model series gets a bespoke aero package, which includes new front and rear bumpers, a roof or a boot-lid spoiler and conspicuously Audi-like gray trim for the exterior mirrors.

Inside, the M Performance versions of the 5, X5 and X6 models get sports seats in black or dark grey upholstery with contrast stitching and embossed M logo, an M leather steering wheel with gearshift paddles, BMW Individual roof liner in Anthracite and interior trim strips in Brushed Aluminium Shadow (X5/X6) or Aluminium Hexagon (5er).

The European launch of all four cars is set for April. Below you'll find the selling prices (including 19% VAT) in Germany:

BMW M550d xDrive -------------- 80 800 EUR
BMW M550d xDrive Touring ----- 83 750 EUR
BMW X5 M50d-------------------- 82 300 EUR
BMW X6 M50d---------------------85 800 EUR