Dear I do have Toyota Vitz 2012 model, about 5 months back change its head assembly due to oil consumption issue and after installing assembly using 5w30. First I pour Toyota taglon as it was only brand available at that time while replacing head assembly and drained it after running 300km only then pour Liqui Moly 5w30 TecAA and drove about 4100km(914km highway drive touches 160km/h) but suppose to add about half litre to keep oil level full and this time using 5w30 Petromin Fully Synthetic. All I need to know current oil mileage is about 3800km and approximately I suppose to add 300ml to keep oil level even little above from full mark. Recently, done CAT clean process. All I want to know shall I use same oil grade or increase by 10w30 or 5w40 fully Synthetic. As I have no idea what will be the mileage of used assembly. Looking forward positive feedback.