Gasoline does not freeze in Georgia. For this to happen, temperatures would need to drop to minus... It's water vapor, not

Gasoline does not freeze in Georgia. For this to happen, temperatures would need to drop to minus 50 degrees Fahrenheit ... and yet, auto parts stores offer a large variety of fuel additives to prevent freeze-ups.

What freezes isn't actually the gasoline. It's water. Even with today's closed-system cars, atmospheric air still will get into the tank and import its content of water vapor into it.

When temperatures drop, condensation forms on the inside walls of the tank. This is liquid water that mixes with the gasoline during driving, but doesn't dissolve in it.

During a night when the thermometer goes well below freezing, the water turns into ice crystals. It doesn't take much ice inside the thin, metal fuel lines to block them completely. The symptom will be a car turning over just fine, but it simply will not start because no fuel is arriving at the engine.

One can use a hair dryer to sweep warm air across the fuel lines underneath the car, and melt the ice clot. Bringing the car into a heated garage, if one is available, takes longer but is much less unpleasant than laying on the frozen ground underneath the vehicle.

Experts advise not to try cigarette lighters, plumbing torches and such because an open flame near gasoline always is dangerous. A heat gun, which looks similar to a hair dryer but is much more powerful, also can present a hazard because it is designed to put out enough heat to melt paint.

Commercially available gasoline additives will do nothing to unclog your fuel lines if they already have frozen up. They are designed to remove water from the fuel by distributing it evenly throughout the fuel, and preventing it from getting concentrated anywhere.

Back in the 1960s, some additives were derided as "snake oil," meaning they did nothing but enhance the flow of dollars out the buyer's wallet. But the modern gas additives made to prevent fuel line freeze-ups have a real function, and they work.

Watching the weather forecast is helpful in determining when such an additive might be needed the most. What's needed is a great deal of moisture at first, which makes condensation form in the tank. Water also can come in with the fill-up at a gas station. After that, a fast, hard freeze will do the damage.

In Georgia, this is the typical sequence in a winter frontal system. A warm front imports huge amounts of moisture from the south. The cold front arrives, soaking the area with heavy rains.

The following day and night will show a steady drop in temperatures, with a hard freeze around sunrise. Frontal systems are best recognized by the presence of a low-pressure cell, and a warm front followed by a cold front.

Both fronts sweep through North Georgia, but the low tends to travel farther north. When you see those three elements approaching from the northwest, it may be time for some fuel line additive.

This is cache, read story here