‘Mothball’ this tactic

Q: Greg, I have a 2005 Mercury LS. While having my car serviced, I overheard two men talking about how to keep fuel-injector nozzles clean. One man said he uses Pennzoil’s “Gumout” Fuel Injector Cleaner every fifth tankful of gas. The other said he drops two mothballs in his ‘98 Mercury every time he fills up. Would I be foolish to try this? — Ray P., Port Ritchey, Fla.

A: Ray, this “theory” actually began to gain more attention when it was said that mothballs raised the octane rating of gasoline.

According to the research I dug up, there are two types of mothballs, and one of them is a hydrocarbon and made of naphthalene. If you drop two of these in your tank, it probably wouldn’t hurt the engine. However, the second type of mothball is composed of dichlorobenzene, which could damage your motor because it produces hydrochloric acid when it burns.

As for using Pennzoil’s “Gumout,” that’s a good practice, as is using a good grade of fuel that already contains fuel-injector cleaning additives.

To make a long story short, don’t put any mothballs into your gasoline.