What's the white crud on my spark plugs caused by?
My husband insists that the white crud that he finds deposited on the spark plugs of my 1998 Camry are the result of using any gasoline other than his favorite brand. I do use name-brand gasoline, but I tend to stop at the most convenient station, rather than go out of my way for his brand. Am I as irresponsible as he thinks? -- Sherrill
RAY: Tell your husband to get a life, Sherrill. That white crud shows up on spark plugs no matter what gasoline you use.
TOM: It's basically ash, sulfur and other unburned components from the gasoline that get deposited on the spark plugs over time. It can be made worse if you use a spark plug that's not hot enough, but I trust that your nit-picky husband has put the right plugs in your Camry.
RAY: But rest assured, that white crud is not doing any harm to your engine or your gas mileage. It's just that spark plugs DO burn down and corrode after a while, and they build up deposits. That's why manufacturers recommend that we do what? Change them every so often!
TOM: And think about this, Sherrill: The differences between brand-name gasolines are so small that the companies have to lure you to their stations by advertising the cleanliness of their restrooms. We think that's as good a reason as any for choosing one brand over another.