We mere mortals take coolant largely on faith. After all, anything that is tested with little colored balls in a turkey baster is way beyond our comprehension.

Left to our own devices, we would just fill the radiator with a garden hose and off we'd go. But not for long.

Antifreeze coolant is designed to keep cooling in temperature extremes far better than H2O, and that's good news for your engine. Coolant also helps prevent the corrosion and mineral deposits associated with nature's version.

Still, it's not foolproof.

"The problem with antifreeze is, if you put too much of it in, it actually doesn't cool very well," says Duchene. "You've got to get the mixture about right."

And don't forget to drain and replace the stuff periodically. This keeps it from gumming up and clogging those heat-reducing cells.

-- Text by Jay MacDonald, illustrations by Brandy Kesl.