You're theory is correct, but I don't think the difference in mass will make much difference at all. Not sure what the density of gasoline is, but I think it's less than that of water, which is about 1 kg/0.001 cubic meters = 1 kg/ Liter._-Night-Shade-_ wrote:I just don't let it sit near empty overnight because too much condensation happens when it's empty, but there have been days where I've driven till it was at E with the light on so that's how I know. Don't forget a full tank makes a big weight difference, you'd have better fuel economy when it's not full.
So full tank is about 50 kg assuming water, but I think density of gasoline is about 750 g/Liter, so about 38 kg.