depend ur engine condition,my car oledi over 190,000km,still using castrol magnatec 10w/40,n change it every 5~6k mileage,no oil comsuption...follow the step fully>semi>mineral>cheap oil,lets say 1 step for 2 year u car also can long lasting for 8 year,just use branded oil n the specification meet the standard,n the importance thing change before the interval mileage recommended :) such like mineral oil change at 4k~4.5k,semi change at 6k~7k,fully change at 12~13k,turbo car or sport car exceptable,need to change more early,wat happen if engine oil comsuption?1st,loss power 2)waste petrol 3)waste engine oil
