Use 5w30 weight oil only just as recommended in your owner's manual.
5w20
10w40
5w30
5w-30
5w30
5W-30 is most recommended for a 2006 Chevy Impalawith a 3.5 liter motor. 5W-30 is most recommended for a 2006 Chevy Impala with a 3.5 liter motor.
10w30
10w30
Should be marked on the oil fill cap
5w20 synthetic blend motorcraft recommended
The Ford recommended oil weight is 5w-20