The R170's supercharged 2.3L M111 four is the community's sentimental favorite for the chassis: 'agricultural' sounding but torquey, reliable, and reportedly good for well past 300k miles. Owners buy it for the blower and handling rather than refinement, noting the supercharged four fits the small roadster's mission perfectly.
Supercharged M111 four-cylinder character (SLK230 Kompressor)
Mercedes-Benz SLK / SLC · driving