In a large bowl, dissolve the sugar in warm water, and then stir in yeast. Allow to proof until yeast resembles a creamy foam, about 5 to 10 minutes.
Mix salt and oil into the yeast mixture. Stir in flour one cup at a time.
Knead dough on a lightly floured surface until smooth. Place in a well-oiled bowl, and turn dough to coat. Cover with a damp cloth. Allow to rise until doubled in bulk, about 1 hour.
Punch dough down. Knead for a few minutes, and divide dough in half. Shape into loaves, and place into two greased 9x5 inch loaf pans. Allow to rise for 30 minutes, or until dough has risen 1 inch above pans.
Bake at 350 degrees F (175 degrees C) for 30 minutes.