Hyundai Repair: Increase MPG: Adding Acetone?, gas milage, hyundai excel

Question
I found a site saying adding small amounts of acetone can improve your gas milage, but it also warned about the possiblity of destroying lower quality rubber fuel lines and seals. I wouldn't mind trying it just to see, but I wanted to know if trying it on a 1990 Hyundai Excel would damage any parts. With gas prices as they are, I am willing to try anything that is less expensive.

Thanks,
Brian

Answer
I'd recommend against this.  If it has the potential of harming rubber components, it could cause costly damage to your car.  

I don't know about the additional MPG claim, but most chemicals that claim additional MPG aren't economically advantageous.  On your car, for example, a product that when added to a tankful gets you an additional mile a gallon would need to cost less than 1/2 gallon of gasoline to be economically advantageous.