They should all go down as the baril price has plummeted ! Happy days !
As for the saving concept most of it is bullshit in my opinion. As Stonefly mentioned the tank is indeed sealed (up to a certain pressure) but air may enter the tank as it empties of course otherwise the fuel pump would create a vacuum. The hissing happens when you have been driving with some fuel and the slashing around and heat expand it and compress the volume of "air" which makes up the rest of the tank. Once you open the filler the extra air hisses out.
Regarding fuel economy I'd say that it's more economical - particularly if you drive in town - to only ever fill it up half way (or even less), that way you're not carrying around extra weight which you would do if you drove around with a full tank all the time.
Having said this, the savings that you can do with 30 kg less weight or even with less evaporation (provided that this is actually true) are going to be negligible, even with the high cost of fuel.
It'l like driving an extra 15 miles because you want to fill up at an economical petrol station and using more petrol to get there in the process than the economy you are actually making because you are paying a fracion less for it.
Site Supporter
its gone down a massive 1p, Petrol has dropped between 5-6p near me.
grew in size & became a Mk3 Mondeo 
s Daily
Previous Topic
Index
