87 should be sufficient and it will run on 87 but if you want the full potential of this engine then Cadillac recommends 91 octane premium fuel.
the fuel tank is 18.5 gal.
put gas in it
Push to the gas station.
The 3.6 engine can take regular (89 octane)
No.
20 gallons
15 ft
They take Regular or E85
They take Regular or E85
Around 13 city, 18 hwy
It is inside of the Gas tank. Get a friend to help.
Try 87 Octane, if it does not "ping" excessively you should be OK