there is 'some' power to be had in prepping your plugs.

The theory behind removing sharp edges is solid. They will build up heat and can lead to detonation.


By cutting back the electrode some, you have less of a shroud around the initial flame cone. Be cause it is less enclosed, it will grow quicker. The fact that combustion spreads across the cylinder more quickly means you'll get a more uniform burn and slightly more power. We're not talking 20hp here. I imagine this could lead to spark blowout in forced induction applications.

Indexing your spark plugs is another thing that yields minute gains. (Setting the sparkplug so that when it is torqued the open side of the cathode is towards the incoming air/fuel mixture/injector)

Now, the splitfire and others like them. Everytime your spark fires, you vaporize a bit of the cathode and a bit of the anode (in the case of platinum plugs this is VERY small). The splitfire and other similar plugs give you more surface area on the cathode, so they will (in theory) provide good performance longer.