I've drained the oil and poured in fresh oil today. But your information was helpful. Now I have one more question: the capacity of engine oil bay as stated on engine cowling is 900 mL; however, mechanic poured in whole 1L of engine oil it and it found the oil level on dip-stick to be just fine. What is the benefit/disadvantage combination of overdoing engine oil when pouring it?
I've tried and tested Kixx several times now in my GD, and I do find id much better than Havoline in that its viscosity remains appropriate for operation even at 1,500 km mark. My usual drain interval of Kixx is 1,500+. Today I replaced my GD's engine oil at 1,800 mark. However, Havoline starts to beg even before 1,000 km to have it drained.
I think we can these details from Pak Filter House (maybe this is the name of famous oil/filter shop on McLeod or Montgomery Road). Plus I am quite satisfied with its performance which I doubt would have been the case if the oil was fake. Please see my experience with this oil here in this thread.