plugs & hp increases

[Barrett Nicholas]

Jeffrey: Another explaination for the HP increases you saw by changing
plugs (and I've heard this attributed to Bosch Platinum plugs in '92
and later 3 series BMWs) is that with that plug you're getting some
detonation and the knock sensor is dialing back the spark advance.
I've used Bosch Platinum plugs in my VW Jetta, it really liked them,
but it sounds like some cars don't like them for whatever reasons.