If it's a daily driver I'd go with either 10W30 or 10W40, I'm going to add a can of STP oil trmt. with my next change since they're no longer putting enough ZDDP in the oil for our old flat tappet hydraulic cams, it is in the STP, I've read it's also in Synpower and GM EOS?
My car came with standard oil, first oil change was to a synthetic blend, next one will be full Mobil 1 + STP. I'll use either 5W30 or 10W30 depending on what I can find with the STP as it thinkens 10W30 up to 10W40 range.
Jon