Preheat the oven to 350 degrees F (175 degrees C). Sift together flour, baking powder, baking soda, and salt; set aside.
In a medium bowl, cream margarine, oil, brown sugar, and white sugar until smooth. Beat in eggs one at a time. Gradually stir in the sifted ingredients until well blended. Mix in oats and butterscotch chips. Drop from a teaspoon onto ungreased cookie sheets.
Bake for 10 to 12 minutes in preheated oven, or until edges are golden. Let set up on the cookie sheets for a few minutes before transferring to wire racks to cool completely.
