I think you should go for Castrol Magnetic engine oil its expensive but will give u double the mileage of others engine oils..
Its a synthetic engine oil and its proves that over 70% engine wear and tear happens when u start up ur engine from cold bcoz the parts at that time are not lubricated it takes 5 to 10 sec to get the engine oil to circulate..Thats why they say at least give 15 sec engine to idle then go.
in Synthetic it sticks to the engine wall and components and reduces the start up engine wear and tear and experts believe can add up to 50000KM or more to ur car's engine life..
Once they tested Mobil 1 Synthetic engine oil and it went up to 14000 Miles remember miles.. with no problems they changed 2 oil filters the engine oil was still in good condition.
Sorry for long taqreer