The time calculation is based on ? is it not true for forced draft lubrication with out any oil pumps ??
I believe The OIL pump in an engine is responsible for lubrication and it should be in perfect order, - please educate me @shahjaha.jhinkur
oil change interval is 5000 km for me since i started driving car, winter or summer ! brand since 2010 is SHELL HELIX before that it was CASTROL GTX