How are oil leaks bad?

Assumming you mean motor oil. Motor oil is meant to lubricate the engine and help dissipate heat. If you loose too much oil your engine may seize bringing you to a quick and possibly terrifying halt. Many people ignore oil leaks which means it soaks into the ground which of course is bad for the environment and also costly since you will have to add more oil every once it awhile. Don't worry about it catching fire, motor oil gets up to 200 and 250 degrees in an automobile but it burns at about 420 degrees Fahrenheit. In other Words unless something other than the engine brings it up to temperature, it will not burn.

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