Mehran needs an API SH oil according to the most updated database
5w-30
10w-30
10w-40
15w-40
20w-50
ALL API SH.
All those suggestions to go for ZIC /others or specially shell 10w-40 oil are amazingly ignoring that most of these oils are either API SL, SM or SN. Specially considering that a senior member Xulfiqar has explained the drawbacks of using such oils in old engines very clearly and if one isn't able to understand or doesn't like the way he explains - they can always hit the INTERNETS!
1 - Oils: What motor oil should I use? Which oil is best for my Porsche or aircooled engine?
2 - Zinc dithiophosphate - Wikipedia, the free encyclopedia
3 - Motor oil - Wikipedia, the free encyclopedia
4 - http://maccc.wikidot.com/zddp-in-motor-oil
you can use API SJ oils but not any newer than SJ, havoline, shell and mobil 20w-50 are perfect for your car.
I personally have been using 15w-40 API SJ for a long time now.. I was using LM Formula Super 15w-40 API SJ but due to some availability issues I switched to caltex delo silver 15w-40, later i found out that shop imports the 15w-40 delo silver directly since Caltex in Pakistan only offers 20w-50 in delo silver so as to remove any doubts i have now switched to Mobil Delvac 1300 Super - 15w-40 API SJ which is available at the mobil1 authorised shop in DHA Lahore. oil change interval = 4000 to 5000 kms.