The story behind BMW's unique quad-turbo diesel engine, its impressive performance, and how it stacked up against its rivals in the X5 M50d.

I've had the vehicle for only a short time, but, so far, I love it. Mine has the V8 engine. It takes a minimum of 91 octane and likes to gulp gas more than I expected, but other than that ...

The third-generation BMW X5 was produced from model-years 2013 through 2018. Quick on its feet and well turned out, this ...