I once put in 15.9 thinkin I might squeeze in 15.

 Recently,I ran out of gas in my driveway thinking  the same thing. I went
inside, came back outside and tried to restart my van and it would start,
but not rev. Repetedly ,it would do this. I opened the engine lid and
started fiddeling with stuff. Fuel pump problem? Electrical problem? Then I
remembered how a vanagon reacts when it runs out of gas. It will start ,
but not rev ,as the last of the gas in the lines is used up. The  fuel
pressure gradually falls off.....

Doing the tank seals  and a new sender is rather far down the list
of "needtodo" items. Behind steering rack,tires,canvas,shift linkage,blah
blah blah.