[citation][nom]HavoCnMe[/nom]she should of just put sugar in his gas tank, that would of been an expensive bill. Especially since she lives in the mountains, im sure her ex probably had a fuel injected diesel truck. $$$$[/citation]As eyemaster pointed out, sugar in the fuel tank wreaking havoc is more of a myth than anything. Even if it just pulled in by the pump (it will most likely just settle on the bottom of the tank), makes it past the strainer, the fuel filter will catch it. If it's a really old vehicle and doesn't have a decent fuel filter, it may plug more than one filter.
Diesels are even better protected from contaminents with better filters (higher capacity, better filtration), often multiple fuel filters, and they get changed more often. They're also expensive as balls on a modern diesel, compared to a typical in-line gasoline filter, but thats part of the additional cost of operating a modern diesel.