The government's National Highway Traffic Safety Administration (NHTSA) has launched a preliminary evaluation of defective tire valves found on more than a million 2007 Ford vehicles. The snap-in valve is said to be a Chinese-made tire component manufactured by the Shanghai Baolong Automotive Corporation for Ford's auto parts supplier, Dill Air Controls Products.

"The original equipment snap-in tire valves may crack due to poor ozone resistance," said NHTSA in documents on its Web site. "Air leakage from a cracked tire valve may result in tire damage, which could affect vehicle control." According to Edmunds, the faulty valve is installed on nearly all Ford cars and SUV's, including the Edge, Expedition, Focus, Escape, Explorer, F-150, Fusion, Mustang, as well as the Lincoln MKX and MKZ, and the Mercury Grand Marquis and Milan.