Three consumer-advocacy groups have sued to overturn a U.S. rule that gives automakers a choice in how they meet a requirement to install tire-pressure monitors in all vehicles, saying it allows "an inferior system," according to a Bloomberg News story by Alison Fitzgerald. Public Citizen, the Center for Auto Safety and the New York Public Interest Research Group filed a petition against the Transportation Department in U.S. appeals court in New York. The rule issued in May is arbitrary because it lets companies such as General Motors Corp. and Ford Motor Co. choose effective direct monitors or inferior indirect systems, they said in a statement. The new rule for cars and light trucks built after Nov. 1, 2003, was passed in response to 271 highway deaths linked to tread separations of Bridgestone/Firestone Inc. tires, mostly on Ford Explorer sport utility vehicles. The consumer groups said the National Highway Traffic Safety Administration (NHTSA) recognized the indirect monitors as inferior yet allowed automakers the option of using them because they are less expensive to install. "To the extent that you have an inferior system and you're relying on it to tell you that your tires are underinflated, you are taking a risk because it does not always tell you that," said Allison Zieve, the attorney for Public Citizen. Tim Hurd, a spokesman for NHTSA, which issued the rule and is part of the Transportation Department, declined to comment.