i normally empty prevoius can and then pour from new oil can,, it takes about 3.2 -3.3l approx and when change filter ,, its about 3.4l - 3.5l,, final chk done nextday before start and if needed to top.
To my knowlwdge, engine has a wet sump where all the oil is collected when we shut it off.
i am told high perf. engines tend to consume oil.. best to change oil before every fast run or 1000km- 3000 km.
and always use high perf. thin oil.