Law enforcement sources tell us ... Rulter's blood alcohol content was ultimately determined to be .06 at the time of his arrest ... which falls safely under California's legal limit to operate a vehicle, .08.
As TMZ first reported, Aguilera was a passenger in the car that morning ... and was arrested for public drunkenness when officers determined she was too hammered to take care of herself.
Hours after the arrest, officials decided they would not pursue any charges against the singer.