WARNING: This page is about a different car, the 2016 BMW Z4, 2015 BMW Z4, and 2014 BMW Z4. However, it is still accessible from the selected car via links, so may be relevant.
TRANSMISSION IN GENERAL 265/5/MANUAL SPORT SPECIFICATION
Oil grade: refer Operating Fluids Specification
Oil capacity
Liters
1.5
Oil fill quantity for initial fill or repair transmission