Interesting, these sparkplugs claims up to 12% increase in HP

Wow a 12% increase in hp! That's make my 375 horse 360 into a 420 hp engine with just a spark plug change! Horsehockey! I know electronics pretty well and can't see how adding a capacitor inside the spark plug can make a difference. If anything it'd slow down the spark delivery because a capacitor has to charge up first then discharge it's spark. I put it in the same group with the other gimic plugs mentioned here. Just my thoughts.