anyone have tried VOLKER IRIDUM PLUGS ? please advice if they are any good or really gain power to the car ? i have C36 1994 and was adviced to use VOLKER either 7ZX-8 SPEC-I OR 6ZR-8 SPEC-II . which one should i use and what is the different between the two ? any advice would be greatly appriciated. thanks

 

This has been disscussed on many forums. The best advice seems to be to stick with the MB recommended basic copper core plugs for the best and most trouble-free performance.