WARNING: This page is about a different car, the 2003 BMW Z8, 2002 BMW Z8, 2001 BMW Z8, and 2000 BMW Z8. However, it is still accessible from the selected car via links, so may be relevant.
FUEL TANK AND MOUNTING PARTS SPECIFICATIONS
Tank volume/reserve
ltr.
73/10
Venting: Via rollover and venting valve, through carbon canister into intake system.