In a small bowl, combine the warm water and sugar. Stir until the sugar dissolves.
Sprinkle the active dry yeast over the water and sugar mixture. Let it sit for 5 to 10 minutes until the yeast becomes foamy.
In a large mixing bowl, combine 3 cups of the flour and salt.
Add the foamy yeast mixture and vegetable oil to the flour mixture.
Stir with a wooden spoon or dough hook until the dough begins to come together.
Gradually add the remaining 1/2 cup flour, a little at a time, until the dough is no longer sticky and can be handled.
Turn the dough onto a lightly floured surface and knead for about 8 to 10 minutes until smooth and elastic.
Place the dough in a lightly oiled bowl, turning once to coat the surface. Cover with a clean kitchen towel or plastic wrap.
Let the dough rise in a warm, draft-free area for about 1 hour, or until it has doubled in size.
Punch down the dough to release the air and turn it onto a lightly floured surface.
Shape the dough into a loaf by flattening it into a rectangle, then rolling it tightly from one short end to the other.
Pinch the seams and ends to seal and place the loaf seam-side down into a greased 9×5 inch loaf pan.
Cover the loaf with a towel and let it rise for another 30 to 40 minutes until it has risen about 1 inch above the rim of the pan.
Preheat the oven to 375°F (190°C).
Bake the bread for 25 to 30 minutes, or until the top is golden brown and the loaf sounds hollow when tapped.
Remove the bread from the oven and let it cool in the pan for 10 minutes.
Transfer the bread to a wire rack to cool completely before slicing.