To help People With their life but it is not good for the enviroment!
Better mileage
Alcohol is cheap and not dangerous to health and the environment like mercury.
advantages= is cheaper and more efficient and does not damage environment as much. disadvantages= may corrode parts of engine, you may have to fill in more often as alcohol runs out quickly.
Alcohol is cheaper than mercury, and if you break the thermometer, it is not toxic.