James wrote:
Last time I changed my plugs was 4 years ago. Plugs don't go back that
frequently unless your engine has problems.

Exactly. I don't know how many people waste money on new plugs because
they are dirty! Clean them! It's not like there are moving parts in
there to go bad! When they show signs of wear, like the electrodes
rounding off, THEN replace them. But, if the electrodes are wearing to
the point where you have to change plugs each season, you've got other
issues.