Haven't posted here for many years (children!). Had a quick search to see if this question has been answered. No luck!

Just purchased H car number 10, a little 2008 Manual Civic Sport. Neat and stock. CLean as a whistle. Just noticed on the first two tanks of fuel that whenthe digital readout reads empty (and I mean EMPTY as all 20 dots in the Full to Empty curve were out and the orange light was shining!), I only get 39 or 40 litres into the tank - brimming! Every spec I can find online here and abroad (redbook, carsales, drive.com.au etc) suggests a 50L tank. What is the story? And if it is 45L or 50L, how do you know when to fill up.

I have never run out of fuel, but I like to run it almost empty so I am not effectively having an extra 10kg of ballast in the car for no reason!! I know this is not a performance car. I have owned type R's and conversion cars and have raced Civics, but I would still like to use ALL of the tank most times!

Any ideas (citing sources or online forum chats) would be appreciated! Thanks!