I helped my friend fix a Ford, and it was ugly. One plug blew out of the head completely. We had to a helicoil in a very awkward location. It appears that the metallurgy in the heads was bad. I've heard about the plugs breaking, but never experienced it firsthand.

has anyone
 

changed plugs and got better mpg? i know some swear by different brands. and some swear by indexing for performance. and some just swear.:lol: i do know that different plugs and the gap can make a huge difference in performance on 2 cycle/strokes , since i have tuned a few. they're easy to tune-only 1 plug. i may try a different brand in my hhr, they don't look very difficult to change to me.after i change out that boat anchor filter housing. any (plug) recomendations?