I want to add diesel fuel supplement to lower the gelling point, but
there are four possible openings on top of the tank. One conrtains a
flip top lid with the number "2" on top of the lid. The second is
attached to the fuel gauge. The third is in the center and requires a
special tool to remove it; so does the fourth at the other end.
Is it one big tank, or multiple chambers? Does it matter where I add