See What Kind of Engine Oil to Use on page 6-14 of your "Owner's Manual", under Section 6: Service and Appearance care - Engine Oil.....
yes you can
SAE 5w20
Low or no oil pressure.
5w-30 is reccomended for the 3.5l v6.
A3387
5w-30 regular oil or synthetic, whatever you prefer.
Use Castrol GTX.
The 2007 Chevy impala takes up 5 quarts of oil.
in the oil pan
5w30 only
A 2002 Impala with the 3800 engine requires 4.5 quarts of oil (5w-30 is recommended).
5W-30