>Anyway it turned out 2 other pilots had put a total of 4 litres of oil in that engine in the last 6 hours and did not think it worth informing maintenance
not great. Far from sensible. But surprisingly close to allowable.
Assuming a 300hp IO540 the max permissible consumption is 0.97Qt / hr or 2 3/4 litres in 6 hrs.
Source :
https://www.lycoming.com/sites/defau...onsumption.pdf