Carbon buildup

Q: Greg, in a recent column you said that a “spongy” buildup of carbon causes some hesitation and start-up problems. How about when the “spongy” carbon solidifies, which it eventually will, and causes serious harm to your engine? From personal experience, carbon buildup caused me to need a new engine, as it was unwise to do just the heads. My question is, what is the best additive that I can add to my gas that will do a creditable job of preventing carbon buildup? — Gerald S., Hiawassee, Ga.

A: Gerald, to prevent carbon buildup, use those quality gasolines I mentioned, like BP’s Amoco Ultimate or Shell’s new V-power fuel.

For readers who already have carbon buildup, you can rid your engine of it by using a professional-quality top engine cleaner.