Can you put synthetic oil in a 1999 Jeep Grand Cherokee lerado?

Answer 1

Yes. The best benefits from synthetic oils are gained when used from the very beginning however. You would be better off using a good quality regular oil and changing it every 3000 miles than putting in synthetic oil and leaving it in for whatever longer interval the oil manufacturer claims. You have a 10 year old vehicle and in my opinion the higher cost of synthetic is not justified. I think the 3000 mile change interval along with a filter every time will be better for your engine than use of a synthetic. You might do some research into the high mileage oils that are currently available.