Hello people. I've scimed through the older threads but haven't found a sure answer. I have a few questions about synthetic oil. I have a 1996 Nissan Maxima 3.0 with 146,000 miles. No noticeable oil leaks or oil burning. Bought the car with 139,000. Runs strong. I believe previous owner used dino oil(not sure) and i have also. Is it fine to switch to synthetic after so many miles? I've heard many mixed opinions. What about GC in this particular vehicle? Is GC good for performance driving or high revving? BTW i live in Northern NJ.