I installed the ZEX spark plugs for turbo cars about 4 months ago. Car ran ok but started developing a miss and then eventually would start missing bad in boost. I pulled the plugs and the ceramic is missing from one of them about halfway down. I do not have a detonation problem with this motor so I am going to write them off as bad equipment. I have run several sets of NGK in the car and will be going back to them for good. I put the new set in yesterday. I just thought you all would like to know before you spend twice the price to get an inferior product in my opinion.

 

The Zex plugs are crap. There's no point in having 3 ground straps when only one of them is going to spark.

 

what he said^^^^^

 

NGK 7's