Chevrolet 2006 HHR Owner's Manual page 316

CAUTION:
{
Never use oil or grease on studs or nuts. If you
do, the nuts might come loose. Your wheel
could fall off, causing a serious accident.
8. Reinstall the wheel nuts with the rounded end of
the nuts toward the wheel. Tighten each nut by
hand until the wheel is held against the hub.
5-68
9. Lower the vehicle by turning the jack handle
counterclockwise. Lower the jack completely.