Coming at the heels of Toyota’s problems with sticking accelerator pedals, news of potential braking problems on the 2010 Toyota Prius and Lexus HS250h hybrid has raised legitimate concerns among hybrid owners. Yet, media coverage of Toyota’s safety issues may be blurring the lines between a potentially fatal problem with the accelerator pedals—resulting in a massive recall of 4.5 million Toyota vehicles—and the hybrid braking issues that may largely be based on perception.

First, consider that the National Highway Traffic Safety Administration has received nearly 200 consumer complaints about the 2010 Toyota Prius’s braking performance—while approximately 103,000 units of the 2010 Prius are on US roads. (Each of these case must be investigated before any conclusions can be drawn.) It’s also interesting to note that in Japan, where the 2010 Prius has been the No. 1 selling car for six months and 200,000 units have been sold, the Prius braking issue “hasn’t registered on the national radar,” according to National Public Radio reporter Lucy Craft. She characterized the coverage in the US as a “hysterical reaction,” compared to the response in Japan.

Some drivers of the 2010 Toyota Prius have complained of a feeling of losing brake power when going over a bumpy surface.

NPR added that Toyota doesn’t believe there are any “defects” and any problems related to the driving experience can be “fixed fairly easily by adjusting some software.” That’s exactly the position taken by Ford to some customer complaints about braking in the 2010 Ford Fusion Hybrid and 2010 Mercury Milan Hybrid. "While the vehicles maintain full braking capability, customers may initially perceive the condition as loss of brakes," said Ford. “There have been no injuries related to this condition.” Toyota informed HybridCars.com that "there is no loss of braking control."

In an interview with local ABC News, Wayne Mitchell, co-founder of a local Prius chat group in Chicago, said, “The sensation you have is like your accelerating, but in actuality you're just coasting." He explained that the brake pedal doesn't feel engaged going over an uneven surface, even though it is. "If you were just to push a little further into your brake pedal, the brakes—the regular brakes—are there. They'll come on and they'll stop the car," said Mitchell.

Ford attributed the sensation to “a different brake feel when the hybrid's unique regenerative brakes switch to conventional hydraulic braking." Ford is planning to ask Fusion Hybrid and Milan Hybrid owners them to bring in their cars to be reprogrammed at dealers at no charge.

Mitchell’s coworker Felipe Torres, who also drives a Prius, said, "You always have braking power, you have the ability to stop the car, but it might make people more comfortable not having that sensation on occasion," said Mitchell.

Aaron Bragman, an automotive analyst at HIS Global Insight, told the Wall Street Journal that some drivers are unfamiliar with the idea that hybrids drive slightly differently. “The brakes are different and the regenerative system is different. It’s a learning curve when you’re driving a hybrid.”

Regenerative braking is a key function of hybrid cars—as well as the plug-in hybrids and electric cars expected in the coming years. These systems have been put to use in hybrids since 1997 in Japan, and 2000 in the US. There are nearly 2 million hybrids currently in use in the United States.

Reprinted with permission from Hybrid Cars