'01 DTS oil & filter question

I have an '01 DTS, which I typically take to my local dealership for all servicing. In the essence of time I am considering taking it to a "quick lube" outlet but wanted to know what OEM oil and filter my caddy uses. I know that the oil cap says 5W 30 but my dealer puts 10W 30 in it. I was also thinking about switching to Mobil 1 synthetic and wanted to get some opinions first. My caddy has 67K miles on it. What brand oil and filter is the OEM of choice? Thanks!

10-30 is fine. Mobil 1 is also fine, but it probably does more for your ego and 'good feeling' than it does for the caddy.
As to the filter, I don't know the number; but the word on the street is to stay away from Fram.