THE IDEA was as simple as it was brilliant. Grab one of the purest M cars BMW ever made, a 2003 M3 CSL, and throw it head to head with its newest descendent, the turbocharged M4.

The task: find out which is best.

BMW M4

The M3 CSL has sweetness, playfulness and predictability the M4 just can’t replicate. And then there’s the noise it makes. The M4 can only dream of such raspy, high-pitched goodness.

BMW M3 CSL