HR200,
I also fly the Robin HR-200 (Brilliant little machine might I add!), and it is
not the same as the HR-100
AN2 Driver,
I don't know much about the HR-100, but I do know that it has a Lycoming IO-360 engine and yes, an incredible 400L fuel capacity! However, I did find this link, which might yeild some answers for you:
http://www.dmjwilliams.co.uk/gbapy_performance.htm
Cheers,
Ox