Making an M version of the X6 seemed an impossible challenge, but BMW proved it could be done. The X6 M handles like a much smaller car. But now BMW is coming out with an X6 M powered by a diesel engine, as if its engineers are constantly seeking a higher mountain to climb. Along with the X6 M diesel, BMW has also come up with the X5 M50d and two 5 Series M diesels, all using the same engine.
The engine that gives this X6 its M badge is a 3-liter straight six-cylinder engine, pretty standard stuff for a diesel. But the secret sauce is three turbochargers, two low-pressure and one-high pressure. Total output comes up to 381 horsepower and, wait for it, 545 pound-feet of torque. It is that sort of twist that gets the X6 M50d to 60 mph in 5.3 seconds.
The suede seats and interior appointments certainly give the cabin a premium sports feel. But hunting around, there was no evidence of an M button, that toggle which in other BMW M cars turns mild-mannered transportation into a ravenous monster.
BMW says the X6 M50d hits maximum torque by 2,000rpm. As redline is at 5,500rpm, expect a lot of quick shifts from its standard eight-speed automatic transmission. The X6 M50d is supposed to achieve fuel economy in the low 30s, although that is most likely a highway number.
The engine is only part of the story in any BMW M car. Handling also needs to be superior. The X6 M50d comes standard with BMW's adaptive suspension technology, which helps make the standard X6 M such an impressive performer. But there are strangely few buttons for drive modes on the console. The simple Sport button seems all that is required to activate M power.