Originally posted by /^Blackmagik^\
contrary to popular belief, spark plugs will not give HP gains unless in an FI application. i have heard that platinum plugs are actually bad for your engine because they burn too hot and will burn pits in your piston head.
NGK platinums come stock in all DOHC VTEC Honda motors and some of the newer motors, so how can platinums ruin your engine.
I still do not like them since they are $$$, copper burns better, and the only reason platinum is used is so Honda can say no major scheduled maintenance till 105,000 miles.
Stick with NGK or Denso for your Honda, there is a reason why they are reccomended.