DrewE wrote:
The on the tank gauge is analog; the scale could be printed in quarters or tenths or gallons or pounds or mols or whatever other units they wanted. I think mine is listed in percent and has bigger marks for the quarter tank points, but I don't recall specifically.
I have no idea why the monitor panel "standard" is thirds (with four lights, one of which is unconditionally lit and hence superfluous). Maybe it's been determined to be the cheapest and least precise option that still appears to be somewhat useful to potential purchasers.
That's my suspicion. 2 sensors give you approximate "thirds" of (some) tank status. More sensors cost a few more pennies per coach and the green eyeshade boys live by pinching pennies.