I think the old el paso brand is just too high in everything as a result of being too similar to flour tortillas... the percentage of corn in it versus wheat is small.
Authentic corn tortillas are made with:masa harina and water!
Old El Paso "corn tortillas" - Corn Flour (29%) , Wheat Flour, Water, Partially Hydrogenated Vegetable Oil, Stabiliser: Glycerol, Wheat Gluten, Salt, Dextrose, Raising Agents: 450a, E500, Emulsifiers: E471, E466 , Preservative: E202, Acidulant: Citric Acid, Flour Treatment Agent: E920.
HOWEVER, I still think they can fit into the sway just fine... I'm just a mexican food snob! :P