When Honda Motor Co. rolled out its latest-generation Civic hybrid, it was sold as the automaker's green car of the future.
But five years into production, Honda has discovered that its high-tech batteries can die years early, a potentially expensive flaw that the automaker has been addressing with a software update that many owners claim has made the car less environmentally friendly.
Jason Marchesano of Overland Park, Kan. said the battery in his 2007 Civic hybrid started losing its ability to hold a charge last year. Rather than replace the battery, which was under warranty, Honda loaded a software program into the car's computer that he said made the car sluggish and slashed the vehicle's gas mileage.
When he complained again several weeks ago, Honda installed a second software update, cutting efficiency further. Today he gets just 33 miles per gallon, compared with 45 when the car was new.
"I've been sitting here scratching my head and asking, why did I get a hybrid?" said Marchesano, a computer consultant whose hybrid's gas mileage these days is scarcely better than the conventional Civic, which is rated about 30 mpg and costs several thousand dollars less.
Marchesano and other hybrid owners fear that Honda has decided to sacrifice their vehicles' performance in order to avoid the huge cost of replacing thousands of faulty batteries, which are still under eight- or 10-year warranties and cost as much as $3,000 each to replace.
Those worries were heightened in recent weeks when the Japanese automaker mailed a letter to more than 100,000 owners of 2006, 2007 and 2008 Civics in the U.S. and Canada warning that their batteries "may deteriorate and eventually fail" earlier than expected. The letter said a software patch would fix the problem.
Honda says the free software update is designed to make the car run better.
"This is certainly not a financial decision," Honda spokesman Chris Martin said. "This is not just to prolong the life of the battery, it also helps improve the performance."
It does that, he said, by ensuring that the battery doesn't crash at crucial times. And, he said, it could preserve the battery beyond the warranty period.
But the software updates have caught the attention of the California Air Resources Board, which regulates vehicle emissions.
The agency, which complained that it was not properly notified of the modification, met with Honda officials last week to determine whether the changes would increase emissions, a potential legal violation that could trigger a mandatory recall, fines or both.
"It becomes a potential air quality concern for us," said John Urkov, chief of the air board's in-use vehicle branch.
Urkov said the meeting was preliminary but noted that Honda had swapped out more than 4% of the batteries in the 2006-08 Civic hybrids in California, exceeding the agency's threshold for acceptable failure and triggering the regulatory meeting. Honda's policy is not to replace the battery until it's completely dead.
"We want to know if they're coming up with a strategy to try to protect the battery so they don't have to replace them," said Urkov, adding that no other model of hybrid had such a high rate of battery failure.
Some drivers contend that the software update has in fact increased their mileage and decreased signs of a fading battery. Happy with the fix, they argue that, at least for their driving style, the car works just fine.
"I haven't really noticed a decrease in mileage," said Joe Goldberg, a Harrisburg, Pa., attorney who got the update late last month after the battery in his 2006 Civic hybrid started fading out three months ago. "I don't lose the battery nearly as frequently as before."
But many other Civic owners contend that the changes have had a dramatic impact on fuel economy and dampened the cars' acceleration so much that they feel unsafe to drive.
Nearly a third of all complaints to safety regulators about the 2007 Civic hybrid are about the car's battery, for example, and the National Highway Traffic Safety Administration said it is in discussions with Honda on the issue.
Many of the complaints, which are anonymous, alleged that the sudden loss of power was a safety issue. The condition "becomes a safety hazard on freeway onramps, passing or any time you need to move fast to avoid something," one complaint reads.
NHTSA "is aware of the issue and is continuing to monitor complaints," said Karen Aldana, a spokeswoman for the agency, adding that it had received no reports of accidents or injuries attributed to the alleged problem.
Honda's Martin declined to discuss the company's meetings with regulators, but said Honda did not consider battery degradation to be a safety issue because the primary source of power in the Civic hybrid is the internal combustion engine.