Does anyone know if FSX actually takes into account the planes weight when figuring fuel burn? For example if I burn off 2,000 pounds of fuel will my fuel burn over the next hour be less because the plane weighs less? I have never noticed FSX doing this.

What I'm getting at here is in planning a flight should I plan the extra fuel to carry the weight of the fuel itself? Again using the example of 2,000 pounds of fuel on a one hour flight should I load an extra 60 pounds of fuel to account for the weight of the 2,000 pounds?