the coils produce the high voltage needed for the spark plug and the DME regulates the timing of the voltage... the coil either produces the voltage, or misses it, as the coil is of inferior quality, or, part of the voltage shorts out to the chassis... Running a "higher" voltage will yield anything - when you crack an egg, regardless if you crack it with a knife, a fork or whatever, the end result is stil the same - the egg is cracked...

that is a sales pitch that may be valid for some other car makes but not for BMW - unless you change the software mapping of the engine...