At the time of its introduction in late 1999, the BMW X5 SUV was either a revelation (for those new to the BMW brand) or an aberration (for those true to the BMW brand). Never before had BMW – or anyone else – combined an accomplished on-road dynamic with such a high degree of utility. Both substance and presence were upgraded in 2011, as the X5 received both new sheet metal and drivetrains. And those drivetrains run the gamut, from an in-line 6-cylinder delivering 300 horsepower to a twin-turbocharged V8 offering 400 horsepower, and the X5 M with 555 horsepower from the same 4.4-liter V8 displacement. At the opposite end of the consumption spectrum is the X5 xDrive35d. The turbocharged diesel provides 265 horsepower and an EPA rating of 26 mpg highway.