I also live in Pak. My car mileage is 90k ( Still going strong) and i use Havoline 20w - 50.

Is this the correct decision in our extreme hot weathers?

 

Well the first number only has to do with starting temp so in the extreme cold you don't want a 20W. But in most even reasonably cold environments it is fine.

And of course it depends on what particular oil you are using. But most modern oils are really good so if you change it fairly often you should be fine.

 

Hmm, so i should shift to 10w - 40 from 20w-50 in winter... right?
BTW i am using Havoline 20w-50 Motor oil ( Non synthetic )