We have dynoed all types of chips on Mercedes and have NEVER seen such an increase on a late model NA motor. The factory is leaving tuners very little to play with these days as they squeeze more power out of the stock program. Those gains were possible a few years ago , not any more. Furthermore some chips with high claims have cause detonation problems.

The fact that they don't have the program ready yet should tell you something. It is basically the same exact program as the SLK320...the the same Bosch unit, same version code, etc...