Best oil weight

[Wolfsbrg8v at aol.com (Wolfsbrg8v@aol.com)]

for a stock scirocco in a hot climate?  Atlanta Ga. .. it gets 
to mid/upper 90's pretty often in summer.  I just switched to 
synthetic oil and put in 4.8 quarts of 10W-30.  Out of curiosity 
I look at the oil chart in the original 84 owner's manual, and it 
recommends 10W-30 for temperatures only up to about º 60 F .

Basically wondering if I need to use heavier oil, and/or if there
is a "best" for city driving in swamp-like conditions.

thanks,
Leo