Pouring sugar into a car's gas tank is thought to be a petty yet effective means of sabotage. As parodied on The Simpsons, it's the preferred revenge method of estranged (and deranged) spouses and partners.
The idea is that the sugar causes the car's engine to permanently seize up, resulting in a costly trip to the mechanic. The guys at Project Farm recently put this mischievous theory to the test. Here is the video.
To find out whether adding sugar to a gas tank really destroys a vehicle's engine, Project Farm conducted a series of experiments on a lawn mower and chronicled the results from inside the engine. Here's what the cylinder head looked like before and after adding sugar:
As you can see, the sugar caused an alarming buildup of residue on the cylinder head. Similar results were observed on the piston and valve, which obviously isn't good news for engine maintenance. With that said, the engine wasn't ruined and continued to function.
Conclusion: while a dose of sugar won't kill an engine outright, it may cause long-term complications for your vehicle. For a full rundown of the experiment, watch the video above.