Normal (unleaded fuel)
The Look The ceramic will have a grayish-tan to white color. The electrode will look new with sharp edges and a slight coloration. There will be no evidence of oil, wetness, or glazing.
The Problem None—the engine runs great
The Fix None
Normal (leaded fuel)
The Look Similar to unleaded fuel, the ceramic will be discolored but with a more chocolate appearance. The electrode will also have a like-new look, but with a slight yellowish coloration.
The Problem None—the engine runs great
The Fix None