Old thread, sorry but.
I just have to chime in and say my VZ uses the same amount of oil as the original poster, who seems to have upgraded to a VE. Oh well.
I took delivery of this at 60000 k and in beautiful condition kept it that way to it's now at 150000k, regular sub 10000 oil changes always with Nulon 5w30. Always surprised that 5 litres or less comes out when 6.5 ltrs go in.
The motor runs very well with no leaks and no smoke.
Thinking next time I might changing to another brand oil first before changing viscosity , maybe Castrol Edge just to see if I still use so much oil.
Unless I can be convinced I am damaging my engine I should stick to the viscosity that has kept the engine strong since I have had it, that's my thoughts, uneducated as they are.