This is something that annoys me quite a bit; kind of like hard-drive manufacturers' claims of "160 GB" when in reality the size is 160,000,000,000 bytes. But that's another issue. I have a problem with the unusable part of the tank. It mysteriously holds an extra 2 litres that I cannot find. When I hit reserve I usually ride to a petrol station fairly soon. Although I've got a tank with a supposed capacity of 13+3 litres, I only ever need to fill up 11 litres! I'm a little hesitant to run it dry on reserve, but how many of you experience this problem? Do the manufacturer’s claims of the size of the fuel tank include all the fuel lines, carbies, and cylinder capacity??? Other than that, I'm a little confused. Thermal expansion with warm fuel doesn't differentiate by 2/13! I'm sure it doesn't matter much with a tourer, but my Hornet (for short city runs) only gets 160 km before reserve! (220 for highway). Anyone else have a major discrepancy with their tank sizes?