@tintin1 has recommended the right oil. Zic m (now known as zic x3 - red bottle) is a very good oil for mehran. But be sure to get it from their website only. Many fakes out there!
Secondly, you have stated havoline formula 10w40 which seems incorrect. Havoline formula is actually 10w30 which is api sn and not recommended for a mehran. However, the havoline 10w40 is api SL and is also usable in a mehran. Again, be sure to buy from their company operated outlets / franchises only.