Best sonic fuel tank gauge ?

[Star-Lord]

You stick them onto the top of the plastic fuel tank and calibrate and they tell you how much fuel you have. Does anyone have any experience with these?

 

[oldgit]

On my boat with plastic tanks they either no longer function or give wildly inaccurate readings.
On poo tank it was eventually replaced with a good old fashioned mechanical float system.
Apparently you are supposed to calibrate it somehow but my grasp of "Putonghua" is somewhat limited .... all I really want to know when its about to overflow.

 

[LittleSister]

Best sonic fuel tank gauge ?​

First catch your hedgehog . . .