<VV> Oil, No Corvair

[Ron]

All you oil experts:
My daughter sent a message as she's very concerned about her Chrysler Crossfire (Of which I'm very envious).  She had the oil changed in San Diego and they used Synthetic 5W-30 whereas the manual calls for Synthetic 0W-40.  I say that it should be fine for the San Diego climate where it never gets cold or hot and it may even be better.  Is this a valid assumption or should I have said something different and does she have a valid concern?
Thanks,
RonH