Turns Out Sugar in a Gas Tank Isn’t as Bad as it Sounds Share Comments It’s a popular trope in movies and TV that vengeful exes and mean-spirited hellions need only pour a little sugar in your gas tank to ruin your car. But how true is that? Donut Media’s Science Garage decided to investigate. And how better than to just throw some sugar in an old car’s tank? Turns out, that apart from an unusual, but not necessarily unpleasant, smell not much happens. But why? Turns out that gas, apart from being a liquid, isn’t a lot like water. So whereas sugar dissolves into water, it just stays crystalline in gas and settles at the bottom of the tank. That means that you likely aren’t pulling anything but gas through the lines if your tank is full. That’s not to say that this is a good idea, though. Like any foreign substance at the bottom of your tank, you probably don’t want to be pulling sugar crystals through your lines and filters and getting sugar in your tank would probably ruin a day, just not the day it’s thrown in there. Basically, having sugar in your tank a little like having rust in your tank: bad, but you can get away with it for a while. So consign this to the pages of TV nonsense along with the ol’ banana in the tailpipe.