Iron cookware improves with age and frequent use unlike that of chemicalcoated cookware which can only deteriorate as you use it You will find that you can cut down on cooking oil once you shift from aluminum or stainless steel pans to cast iron pans but it will not be cooking on Teflon coated nonstick pans as well Cast iron pans keep food from burning If you were to keep a iron pan on the stove and start cooking immediately as you would do with an aluminum pan the food is likely to get burnt in places That is why they have to be preheated prior to cooking