New polyester fabrics now make possible, without the need for a coating, materials offering low gas permeability, low fabric weight, compact foldability, and long term durability for use in automobile airbags. These new fabrics are the result of advances both in yarn technology and in weaving and finishing technology. Testing of these new fabrics was focused on its gas permeability and on the stability of this permeability over time. Test results showed these properties in the fabrics to be far superior to those of nylon 66 fabrics. A review of the underlying economic factors of the new fabrics shows that it should also enjoy cost advantages over both coated and uncoated fabrics of nylon 66. Evaluations of the new polyester's long term stability were especially rigorous and were conducted under conditions of humidity and heat. From the results of these tests, it may be concluded that the new polyester fabrics are well suited for use as advanced uncoated airbag fabrics.