Salaam. I am requesting for some expert advice for the engine oil for my Mehran 92. Alhamdulillah it is doing good but being a novice, I haven't really checked the type of oil i am getting for my Mehran. It is a Petrol & CNG car and I change the engine oil at 3k to 4k kilometers. I have been using Shell Helix for CNG lately. Please help me with the type and make of the engine oil i should be using for my car.