While watching the niners triumph over those heathens in Dallas yesterday I saw an ad for splitfire sparkplugs, complete with a testimonial from "Truckin'" magazine (now doesn't that inspire confidence?), that claimed the damn things improve horsepower. Anybody have any first-hand experience/data? Or just opinions? And I apologize to you Dallas fans. I'm sure you don't *all* pull the wings off flys in your spare time ;-)