Originally Posted by
azjug
Finally changed the plugs after 13 years, (50000) miles. The car really didn’t run badly, all the old plugs looked good and were still close to specs at .040 - .043. No problem pulling the old plugs. Regapped the new plugs to .034 and the car seems to have better and smoother speed from zero to redline.
original plugs
If the suggested gap is 1mm (.039”) why would you go to a much lower gap size, just wondering.