I used to be sceptical about the advice given about using genuine or OE spec spark plugs until a couple of years ago, when I experienced the most bizarre faults on a Renault. (see link below).

Trust me when I say, that if you were stood next to a bloke in the pub, explaining the faults that I had experienced, you would have been doing the Gareth Hunt "Nescafé Hand Shuffle" You literally wouldn’t believe it!


http://members4.boardhost.com/ukautotalk/msg/archive/1154378755.html

Never underestimate the humble spark plug!