420 horsepower

The heart of the M56 (and the primary reason you'll pay a whopping $12,500 more than for the M37) is hidden beneath this plastic shroud. The 5.6-liter V-8 engine outputs 420 peak horsepower and 417 pound-feet of torque. But don't go thinking of the M56 as a brute in a suit; the power delivery is refined, smooth, and (for better or worse) understated.