I saw some references to adding sugar to gasoline. The old story about ruining an automobile engine with the addition of sugar to the fuel tank is misinformation. Sugar does not dissolve in gasoline. Problems could be caused by sugar granules, but filtration will generally keep solid particles from entering the fuel delivery system. Large amount of sugar could theoretically clog the filters and result in a need to remove/flush the tank and replace the filters.
Basically, sugar would act like most other solid foreign particles and cause fuel delivery problems. But it won’t dissolve and gum-up an engine.