Assertions that the Toyota software change decreased the car's fuel economy are contained in a lawsuit seeking class-action status filed this month in U.S. District Court in Los Angeles. "Unbeknownst to drivers, Toyota reduced the vehicles' fuel efficiency, which is the main reason why consumers purchase Priuses," it alleges. The suit by two Toyota owners, filed by Los Angeles attorney Skip Miller, contends that Toyota's inaccurate fuel efficiency claims violate various consumer protection laws and result in fraud, false advertising and breach of contract.
Roger Hogan, who owns two big Toyota dealerships in Southern California, has sued Toyota, alleging that more than 100 Priuses have come to his service departments with failed inverters after the software fix was made.
Hogan's suit said that Toyota was slow to notify owners of the defect. It said that the company waited several years to issue the recall for the basic Prius after knowing about the problem and then waited another 18 months to extend the recall to the Prius V.
Toyota officials at the company's U.S. headquarters in Texas issued a statement disputing the allegations in the class-action suit, saying they are without merit. They previously said the Hogan suit is without merit.
"Toyota's focus remains on the safety and security of our customers, and we stand behind the effectiveness and appropriateness of the Prius inverter recall remedy," the statement said. "Due to the pending litigation, we cannot address the specific fuel economy claims in detail at this time, however, we intend to defend against them vigorously."
The company notified the California Air Resources Board of the software change in January 2014, saying that that it made "no significant difference on emissions and fuel economy," according to a board spokeswoman. NHTSA referred questions about the performance to the Environmental Protection Agency, which did not respond by the time of publication.
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The Times interviewed more than a dozen Prius owners who described reliability and fuel consumption issues with their Priuses. When the inverter overheats, the car can suffer a total loss of power or enter what Toyota calls a "limp home mode." When it happens, the dashboard lights up with warnings.
Kathleen Ryan, a Marina del Rey Prius owner who got the software fix in 2014, was driving in the fast lane on the 91 Freeway in January, cruising along at 70 mph, when suddenly "it felt like somebody pulled the emergency brake."
The car slowed down to 15 mph and Ryan had to cross three lanes of high-speed traffic that was swerving around her slow car. Several California Highway Patrol Officers on the shoulder, who had stopped to deal with a stalled big rig, told her she was lucky to be alive, she said.
"If I had been in an accident, nobody would know how it happened," said Ryan. "They would say, 'Oh, this old lady doesn't know how to drive.' If somebody dies, we wouldn't even know how it happened."