Please excuse me for being devil's advocate here, but I have some techincal questions - hopefully someone out there can answer them. The crank pulley is one of six pulleys connected by the belt. How will replacing one of them make such a big difference? Surely it would make some sense to have all of them replaced with lighter material, or at the very least the crank and alternator pulleys. Are the claims of this product realistic at 5-10% increase in power? Even 5% on a sportivo would equal an additional, what, 5kW ATW? And supposed better fuel economy, faster RPM, less wear and tear etc (yay!). I was also reading through the workshop manual - replacing the part seems time consuming - is $50 a reasonable price for installation? Less, more...? Also, why would a mild undercrank pulley not be the way to go (such as unorthodox's one). Lightweight, smaller (but would you need a smaller belt, so an additional cost)? And the other clincher: the dreaded voiding of the engine warrantee if it all goes to the fan. Any thoughts? Just some questions that have been running through my mind. Still interested though.