The Great Myth: Sugar Can Destroy a Car’s Engine

It’s a car legend, passed down from generation to generation, that pouring sugar into the gas tank of a car will ruin its engine. The problem is, it’s just a myth. Sugar doesn’t dissolve in gasoline; it stays in granular form. Engineers at Bosch, one of the auto industry’s main suppliers of fuel system components, say they have never seen an engine damaged or destroyed by sugar in a gas tank. A sugar crystal is about 200 microns, a measure of size for small particles. Filters in a car’s fuel system capture particles much smaller than that, so suspended sugar granules in the gasoline would be caught by any one of several filters surrounded the fuel pump pickup in the gas tank. Even in engines equipped with a carburetor, which doesn’t have fuel injectors or their individual filters, there’s a low chance that sugar would ever make it that far into the engine past all the other filters in the system. Sugar is roughly twice as dense as gasoline, and particles denser than fuel settle in pockets of low-velocity flow. If someone did drop sugar into your gas tank, all you’d have to do is drop the tank to clean it out and replace the sock filter. Your engine would be fine.