Since my extended warranty ran this year I just started doing my own maintainence on the car (i usually take it to firestone) and started doing some of the preventitive maintainence I found on the forums recently. this weekend I decided to change out my plugs for some NGK Iridium plugs and when I did swap them out i noticed that the old Denso PK20PR11 double platinum plugs were gapped quite wide. 5 were anywhere from .050-.055 but one was .073, they were replaced out 3 years ago by firestone and I drive less than 10k per year. this year on the same cylinder as the plug that was .073 the coil went bad and had to be replaced.

did running the spark plug that was .073 kill the coil? and what effect will the wide gapped plugs have on the engine? btw the new ngk plugs were .043-.044 out of the box.

thanks
James

 

The .043 is Nissan spec. A wider gap makes the coil work harder so it could have caused the coil to fail. A wider gap also reduces the performance as the spark will not be as robust as the energy is being used up trying to jump the gap.