I was sitting at home one day when I felt a strong hunger overtake me. So I grab my keys and hop in the car. A quick glance at my gas gauge showed I had exactly half a tank. I drive a few miles over to the local burger shop, park, and head inside.

After I finished dining, I once again hop in my car to head home. After putting my keys in, I notice I now have a hair over half a tank of fuel.

How did I end up with more gas than I started with?

It sure wasn't the burgers.

  • 1
    $\begingroup$ I don't think this is lateral thinking; fuel gauges are notoriously inaccurate $\endgroup$
    – Matt
    Sep 26, 2019 at 18:34
  • 1
    $\begingroup$ @Matt - Yes, that's true - but not in the particular way described. Without some particular set of conditions obtaining (see my answer for the most obvious), the gas level will not increase or appear to increase without actually adding fuel. $\endgroup$ Sep 26, 2019 at 18:37
  • $\begingroup$ @JeffZeitlin Your answer only applies the knowledge of fuel level sensors. I don't see any sideways thinking there $\endgroup$
    – Matt
    Sep 26, 2019 at 18:41
  • $\begingroup$ @Matt - The lateral-thinking comes in when you have to come up with reasons for the anomalous readings. $\endgroup$ Sep 26, 2019 at 18:42
  • $\begingroup$ I feel like it should be replaced with the situation tag... $\endgroup$
    – Duck
    Sep 26, 2019 at 22:05

1 Answer 1


When your car was parked at home, it was parked on a hill such that the fuel tank was tilted to move the fuel away from the fuel level sensor. When your car was parked at the burger barn, it was less tilted, or possibly tilted in the opposite direction.

  • 1
    $\begingroup$ Yep. Question was inspired by real life events. $\endgroup$
    – Veskah
    Sep 26, 2019 at 18:36

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.