The design philosophy of the different fuel level indicators (fuel gauge on the EFIS, Site window on the side, or the mechanical float gauge )on the RV 12 is to show you how much below full the fuel level is in the tank.One for the oldies. I have early 12 with the visual fuel window. I later added the fuel gauge. When the gauge says full (bouncing off the top) the tank is still not full. Possibly one for Scott. Where should it show in the window with a totally full tank?
The gauge center for the EFIS is at the very front of the tank. The mechanical float gauge is mounted higher at the midpoint on the tank, so I think it measures a higher fuel level than 16 gallons.The Moler gauge shows full when you have about 16 gallons in the tank, not sure about the visual tank window as I replaced it with an aluminum panel when I build the tank. The tank holds 19.8 gallons, however the gauge(s) max out at 16 gallons (PAP section G8 only calibrates the fuel to 16 gallons). If your tank window is not marked from the PAP calibration procedure, you may want to recalibrate to match up the float gauge, Moler gauge, and tank window levels.
John Salak
RV-12 N896HS
View attachment 70036