Fuel Gauge Lies

Does it seem like your gas gauge stays on "Full" for a long time before lollygagging down to the halfway mark? Then does it skip almost immediately from half to one-quarter? Have you driven seemingly forever with the fuel warning light on?

By Design Fuel gauges are, by design, pathological liars.
A retired auto company engineer, who requested anonymity, confirmed what many have long suspected and observed: Fuel gauges are, by design, pathological liars.


You wouldn't have it any other way.


And here's proof: When digital gauges hit the scene, this engineer programmed the fuel gauge to say "Full" when it was at its maximum 18-gallon capacity. When the fuel level dropped to 17 or so gallons it said (what else?) "17." Immediately, the company was deluged with complaints that the car was producing poor fuel mileage. The company tested the "problem" cars: All made the advertised miles per gallon. After talking to consumers, this engineer figured out the problem: The drivers weren't complaining about miles per gallon, they were irritated that the gauge didn't stay on "Full" for very long. (This car was sold largely to retired people who have time to worry about such things.)


The engineer came up with a solution: He recalibrated the gauge to skip "17" and go straight from Full to 16. The complaints evaporated.