The midsize luxury SUV that put the “sport” into the SUV equation, is now kicking it up a notch. The big news for the BMW X5 is the addition of a single letter: M. With that small designation, comes big performance numbers. A new twin-turbocharged V-8 engine produces a whopping 555 hp, which is enough to launch this 5,000-pound monster truck to 60 mph in a scant 4.5 seconds—a time that matches the current generation M3. Also new for the 2010 is the X5 xDrive35d—BMW’s first SUV to arrive stateside with a diesel power train—and it will go head-to-head against the Audi Q7 TDI and the Mercedes-Benz ML350 BlueTEC. Regardless of the model variant, the X5 continues to emphasize the driving experience over ultimate utility, which is exactly what made it so popular in the first place. Pros: With 555 hp, the X5 M is at the top of its game. Cons: Lacks the curb appeal of a Range Rover.