In a medium bowl, bowl, beat together the white sugar, brown sugar, oil and shortening until smooth. Stir in eggs and vanilla, beating well after each addition. Combine the flour, cream of tartar, baking soda and salt, stir into the sugar mixture. Finally , fold in the chocolate chips. Drop by heaping spoonfuls onto an unprepared cookie sheet.
Bake for 8 to 10 minutes in the preheated oven. Remove from baking sheet to cool on wire racks.
