i have been searching for some time now on this board and others and have read many many posts regarding this, but most are inverse or old threads. i cant seem to find the info i am looking for. it seems that honda used to recommend 5-30 and then switch to 5-20. many posts regarding whether folks should switch from the 30 to the 20. i have the opposite question.

my 02 LX 4cyl Accord oil cap says 5w-20. i have 96K on it and have always used regular honda dealer dino oil. i live in VA and it rarely gets really cold, maybe in the winter a couple times in the 10s or 20s. and in the summer, it gets into the 90s.

1. would there be a benefit to using synthetic with so much age on the engine?

and

2. would it be bad to use 5w-30? i believe that the second number relates to hot operating temps, so what would be different in the engine with the 20 versus the 30?

thanks