Most owners manuals suggest spark plugs every 30k, who cares if you "can" go longer.

Does anybody listen, have you ever dealt with threads pulled out of heads and plugs broken off? $36 seems like cheap insurance to me.

Sure there are "better" plugs out there, so you buy a $8 ea plug and 100k later you try and take them out to see if they realy didn't wear out, but they are stuck...see ya in the funny papers.

SD