In a large bowl, combine 2 cups flour, sugar, salt and yeast and mix well.
In a small saucepan, heat water and oil until very warm (120-130°F). Add warm liquid to flour mixture, blend at low speed until moistened. Beat 3 minutes at medium speed. Then stir in 2 1/2 to 3 cups flour by hand until dough pulls cleanly away from sides of bowl.
On floured surface, knead in 1/2-1 cup flour so dough is smooth and elastic, about 5 minutes. Place dough in greased bowl and cover loosely with greased plastic wrap and a cloth towel. Let rise in a warm place until doubled in size, 30-60 minutes.
Grease two loaf pans. Punch down dough several times to remove all air bubbles. Divide dough in half and shape into loaves. Place in bread pans, cover and let rise until dough fills pans and loaves are about 1 inch above the pan edges (about 30-35 minutes).
Preheat oven to 375°F. Uncover dough and bake for 40-50 minutes or until loaves sound hollow when lightly tapped. Immediately remove from pans; place on wire racks and brush with melted margarine. Cool one hour ot until completely cooled.