Haha... Sorry for the mislead on the 10% and 20%... In simple it decreased about 1 litre after 9000 kilometre mileage. So, is that you meant it is normal in Malaysia's weather? as we drove the car daily... The time frame for 9000 kilometre is around 5months plus.. :laugh: Please share...Thanks in advance.The difference between 10 and 20% is (Either 50% or 100%! What do they say about 'Lies, damned lies and statistics...) let's call it a wide margin.
Over 9000 miles in the warm Malaysian climate, and always providing the dip stick shows your level is not approaching the 'minimum' mark there does not seem to be much cause for concern.
If, on the other hand, you haven't checked your oil level for a long time (maybe more than one month?) then you are due a slapped wrist!!