ANN ARBOR, Mich. -- Affinia Group has filed suit against one of its competitors, alleging that the company is competing unfairly by falsely advertising the quality of certain brake rotors for cars and light-duty trucks.

According to Affinia, testing by a respected independent laboratory has shown that certain “lightweight rotors” made by the defendant, Dura International of Rancho Dominguez, Calif., weighed significantly less than OE specifications. However, Affinia said it believes weight is not the only concern. The company’s complaint alleges that these rotors were structurally weaker and significantly more prone than their OE counterparts to crack and fail in performance tests.

In a press release issued yesterday, Affinia stated that manufacturers and importers of aftermarket, or replacement parts have a tremendous incentive to expressly state or otherwise imply to potential purchasers that their parts are consistent with OE specifications and that their performance and durability are consistent with the performance and durability of OE parts.

"Most do-it-yourselfers and auto repair shops rely on such advertising statements because they lack the technical expertise to know whether a part actually meets or exceeds OE specifications and performance," Affinia said in the statement. "If potential purchasers are told that aftermarket parts from competing suppliers are of comparable quality - i.e., meet or exceed OE specifications - price differences between competing products become significant. “Lightweight Rotors” cost less to produce. They are, however, more likely to fail than parts that meet OE specifications, which can create safety risks. Despite the fact that Dura’s "Lightweight Rotors" do not meet or exceed OE specifications, the company continues to expressly state or otherwise imply that every unit meets or exceeds OE specifications and performance. These false claims give Dura an unfair advantage over Affinia. Dura’s false and misleading advertising creates a motor vehicle safety risk, and Affinia, in its lawsuit, is asking the court to halt it."

Affinia said it believes that Dura and other companies began introducing the “lightweight rotors” into the North American market in the summer of 2008 and that the design changes were based not on engineering or performance criteria but on some other criteria, such as a desire to reduce mass and control costs.

Affinia seeks to enjoin Dura from making false claims for its brake rotor products or falsely implying that its “lightweight rotors” meet or exceed OE specifications and performance. Affinia has also asked the court to order Dura to publish corrective advertising disclosing that their “lightweight rotors” intentionally deviate from OE specifications, have not been tested to meet or exceed OE specifications and performance, and have not been subjected to independent engineering validation.

Affinia’s suit, filed in U.S. District Court, Richmond, Va., does not address Dura’s entire product line, only Dura’s “lightweight rotors.” Affinia seeks damages and has requested a juried trial.