Iridium plugs are supposed to give a more powerful spark since the tip is very small, very little resistance.

IMHO for 800 pesos per piece, its NOT worth it unless wala ka na magasutusan sa oto mo.And the iridium plugs are very prone to corrossion, not sure why.

WHen checking the plugs, look at the color of the tip. Dapat rust / orange / reddish-brown. If white, you are running lean and burning up oil. If black, you are leaking oil into the plug holes or running way too rich.