Oil/Fuel

I recently bought an 03 CTS sport luxury (pick it up tomorrow) and was wondering what oil and fuel are you using in your '03CTS's?
 
Cheers.

Car is designed to run on 87 octane. Recommended oil is 5w30 conventional oil, as long as API sunburst is on oil bottle it will be fine. 04 required 5w30 MOBIL 1 whiching up to it is up you.

Thanks,  I picked up the car this morning, the seller says he was running Sunoco 94 in it. Will this fuel run too hot? (My thanks to Cadillac for the clock inplace of a temperature guage) and Castrol Synthetic.