This infact apparently appers to be the problem of two things, first definitely the engine power viz a viz body of the car and secondly availabilty of good grade oils in pakistan. I suggest to please visit a workshop named something like CONCEPT MOTOR OILS in Plot No 159, St-9, I-10/3. Tel Nos are
They infact have imported all ranges of motor oils (especially LIQUI MOLI, a germen oil), They dont sell it in the market but change it in their workshop. Let me tell you it is economical as well.
Go and consult them and try it once I am sure you will get the result. However can contact me on 03005294929 Waseem