If you’re still worrying about getting bad gasoline from Stop N Go. relax. The gasoline at all of the chain’s local stores was tainted with sodium hydroxide in mid-June, but that was just a freak incident, and Stop N Go fired the gasoline contractors who were responsible. So you can forget about sodium hydroxide and start worrying about what might really mess up your car’s engine. Some sinister compound from a James Bond movie? Nuclear fallout? Or-
“Water” says John Herman-son of Dallas’s consumer protection division, “is the most common contaminant.” And the problem is not confined to Stop N Go, The fill-lids on most gasoline stations’ storage tanks are set down into a “well,” and sometimes the employees don’t completely seal that lid. When it rains, in pours the water. All gasoline storage tanks have some water in them, but fortunately, gasoline floats on water, so the water sinks to the bottom of the tank where it stays until the tank level gets low, when water could be sucked into the pump. Or, when a tanker truck dumps its load of gasoline into the tank, that stirs up the gas and water, and if you fill up while (or shortly after) a tanker truck makes a delivery, you’re going to get some watered-down gas.
The second most common contaminant, says Hermanson, is alcohol. In Texas, it’s legal for gasoline makers to add alcohol, which increases octane, without telling the customers. That’s not a problem for older cars, but the new ones with fancy computer systems and fuel injectors can be damaged by alcohol. In fact, some car manufacturers void their warranties if the car uses fuel with alcohol. The best way to avoid alcohol is to buy from stations advertising that their gas is alcohol-free. But there’s another way, says Hermanson: “alcohol mixtures smell differently than common gasoline- almost spoiled.”