Eli5: why is it bad to put sugar in the cars gas tank?

Question

Does it really mess up the engine?

In: Engineering

Answer 1

If it’s a diesel – nothing unless amount of sugar is enough to block the fuel filter. For pure gasoline – same. However a lot of fuels are now Eco and contain some percentage of ethanol (between 10 and 85%). Sugar dissolves in ethanol, but how it can affect the engine – no one checked as far as I know.