I was in a BMW performance shop in Pompano and they sell this additive called EFS Combust and they swear by it. Says it makes a little more power and torque and depending on how you drive, you use one ounce per 15 gallons for street driving and 3 ounces per 15 gallons for track days. Does anyone have experience using it? Rennie, the owner says for street driving, he puts 87 octane plus EFS Combust in his M5 and the engine does not detonate. Any body have any similar experience?