Honda asked me to apply the Civic hybrid battery pack software upgrade patch sometime end of 2010.after applying the patch the mileage on the car went down from 45-49mpg to 35-40mpg and also reduced acceleration from a red light or stop sign - car just drags to get accelerated. Complained to Honda dealer many times and they keep telling me its the way im driving and nothing wrong with the car. I have also joined the Honda Civic hybrid class action lawsuit. This is absolutely un-acceptable to give false information to the customer while selling the product and I feel cheated.

- West Haven, CT, USA

I purchased a new 07 Honda civ hybrid and from the start never got close to the mpg as advertised.I had the car looked at by Honda dealer multiple times and they very found anything wrong and would comment that car was within spec. 21/2 years later and in the summer I experienced when the I was in heavy traffic and high temperature with all electrical options on ac, nav, radio, etc. The hybrid battery would drain and not keep charge and the car would operate sluggish, no power, no acceleration and basically unsafe to drive. Th car drove that it had run out of gas.I experienced this 3X in 2 weeks as I was exploring and documenting the symptoms.I took it back to the dealer and it was the time of the software update.they updated the software and they would not replace the batteries even though we indirectly agreed (dealer mechanic did but not Honda corporate..since they declined to replace battery) over time that the battery had degraded due to design flaw.after the software update the car driving characteristics changes.engine idles at higher rmp (higher keeps the battery better charged), the power to pass a vehicle on the highway (my wife would press on the accelerator to pass a car on the highway and the car did not respond almost causing accidents). Considers it unsafe and refuses to drive it and put kids in it.I had de aler look a it for a few days working with the Honda technical team. Final assessment was did not find anything wrong and it is driving within spec.how can that be?the car no longer has power, cannot dependently pass or overcome a car on the highway in normal driving speeds and when you stress it traffic on a hot day and run the normal equipment ac the car feels like it is running out of gas and the hybrid batteries are not charging and are not operating the car as you would expect a car to operate.the software update made the car worst.the car is unsafe!

- Fairfax Station, VA, USA

The Honda Civic hybrid ima system has been inconsistent and a worry since I bought the car. The charge level varies wildly within minutes, releasing the braking charge mode unexpectedly while traveling downhill, resulting in rapid acceleration. While going uphill the ima system suddenly shows no charge and the engine is unable to keep the car's speed constant, resulting in rapid deceleration. The software update that was said to fix these problems resulting in no change to the problems but a considerable reduction in mpg. The engine refuses to stop at red lights and instead remains at idle - wasting gas. I have service records covering the entire history of this car which documents my concerns and complaints. The Honda service department was never able to find any problems with the ima. I continue to drive this car but am concerned for my safety and the car's reliability. Anything you can do to help identify and remedy the ima problem will be greatly appreciated.

- Santa Barbara, CA, USA

There is a potential for the voltage converter that relays power from the integrated motor assist (ima) system to the vehicle's electrical components to fail..a cvt doesn't actually have gears, so the system uses electronics to direct the transmission to up- or downshift in specific ways when a driver hits a paddle.battery loses charge suddenly and power is significantly lost to the point where acceleration is not possible. This has created several unsafe driving condition in highway and expressway entrances, as I can not get in safely or maintain safe speed during driving. This incident has repeated many times in the past three years. Battery indicator drops to zero bar or one bar and power is lost significantly. Sluggish to poor acceleration, especially in highway merge situations placing owner is dangerous situations. When battery charged at least 50%, acceleration is acceptable as the ima assist in acceleration.the vehicle's hybrid ima system (integrated motor assist) has been steadily deteriorating the hybrid battery system must recharge so frequently that battery assist is available less than half the time. When assist is unavailable, acceleration is dangerously low, making common driving situations such as left turns, freeway onramps, and merging into traffic unpredictable and quite hazardous. Honda's only response has been a series of ineffective software updates. Honda will not replace the battery under warranty unless a warning light appears. Yet even the current severely degraded performance of the battery does not trigger that warning light. I have been in several near miss situations when acceleration was so sluggish that I was nearly unable to evade a dangerous traffic situation.

- Garden Grove, CA, USA

We own a 2007 Honda Civic hybrid. We strongly believe this car is unsafe. In 2010 we brought the car into a Honda dealer after the ima light came on. Instead of replacing a bad hybrid battery, the dealer instead "upgraded" the ima software. As a result, the car has lost mileage. But far more importantly, it has lost any acceleration. The software doesn't use the ima (electric booster motor) in a manner that provides any acceleration to the car. In fact, as best as we can tell, the ima (integrated motor assist) is mostly turned off. So we have a smaller combustion engine than the conventional Honda civic doing the work of what should be two engines. The primary and booster. We constantly have a difficult time in gaining freeway speed to properly merge onto the highway. This is impossible if the on ramp is on a hill or incline. We have had several close calls and near accidents. As a result we firmly believe this car is un-safe. We urge you to open up a safety investigation into the 2007 Honda Civic hybrid. If these hybrid batteries were replaced, as they should have been under warranty, this car would not have a safety acceleration problem. Honda refuses to do so. We need your help. Sincerely,

- Mesa, AZ, USA

My wife owns a 2007 Honda Civic hybrid. I had the software update done on my car in 2010. Since the update, the car has not idled when I bring the car to a stop, instead it moves little further, and there is that danger of hitting the car in front of me. Also, once the vehicle comes to a stop, and I start moving again, the car goes backwards a little. If the car behind me is very close to my rear bumper, this Honda Civic hybrid car would actually hit the car in the back.

- Manalapan, NJ, USA

Contact owns a 2007 Honda Civic hybrid. The contact stated while driving up a hill, the vehicle began to hesitate and the rpms increased. The vehicle was not taken to the dealer for diagnostic testing. The manufacturer was not made aware of the failure. The vehicle was not repaired. The failure and current mileage was 60,000. The consumer stated the issue involves lack of power and acceleration. Which was caused by a software update issued by Honda. Honda is having an issue with the batteries dying prematurely. The update that was installed turned off the assisting electric motor to save the battery. Thus, resulting in lower miles per gallon and the lack of power and acceleration.

- Irvine, CA, USA

When pulling out onto a busy 55 mph highway from a side street, my car unexpectedly was unable to provide any electrical propulsion from the hybrid motor. The hybrid battery state of charge indicator was at 6 out of 8 bars of battery level while waiting at the stop sign, but when the demand for electrical assist was given, the battery level immediately dropped to 2 out of 8 bars and provided little or no hybrid motor assist. My vehicle struggled to accelerate up to speed of oncoming traffic, even with the accelerator pedal depressed all the way to the floor (wide open throttle). Luckily, the oncoming traffic was able to react quickly enough to avoid a collision, but I do not feel safe putting myself and other motorists at risk like this. This vehicle was never designed to operate solely on the gasoline engine, as it is under-powered by design and dependent on assistance from the electric motor. The car has since had several occasions where the battery level has unpredictably dropped and lacked hybrid electric assist. My main safety concern arises not only from this lack of propulsion from the designed manufacturer's specifications, but in the unpredictability of to what magnitude the acceleration is affected. Usually the vehicle operates correctly and is able to provide at least some electric assist, as predicted and intended. However, it is the rare and unpredictable occasion that it does not that could lead to a serious accident.

- Cary, NC, USA

The car became unsafe to drive following Honda's software update 10-034. All owners were asked to have the update performed to prevent hybrid pack deterioration. The letter listed multiple situations in which hybrid assist and braking will be reduced. As a result of the update the car has markedly reduced assist, and at unpredictable times no assist whatsoever. At least once a day, at a random time, battery soc drops to 2 bars, all assist is disabled and then the so-called recalibration is performed where the car fully charges the battery to 5 bars, then jumps to full 8. on average that last about 8-10 minutes as documented in multiple youtube videos on the subject. During all that time no assist is available, and additional gas engine power is being used to charge the pack. The gas mileage suffers as well as I am driving at 3-4K RPM instead of the usual 1-2K.. I've experienced multiple situations where such a drop happens when trying to merge on an uphill highway with vehicles behind me almost rear-ending me while I am flooring the gas pedal. I've had that happen before left turn when after a quick glance on the gauge and seeing it full, I'd start turning only to see the pack drop and the car slow down significantly. A related problem is reduced/unpredictable braking. When the battery is cold and the car idles higher than usually, all regenerative braking is disabled and it takes a significant effort from the driver to stop the car. Multiple complaints to the dealer were met with "operating as designed" and "the update does reduce the power". lately, I've been simply referred to become a party of class action suit against Honda, as the dealership is unable to help with anything listed in that suit. As a summary, the car has unpredictable losses of braking and acceleration and a markedly reduced mileage which undoubtedly violates epa rules.

- Penfield, NY, USA

Bought 2007 civic Honda hybrid on feb2,2007. I was told 50 miles/gallon, but it averages only 34 miles/gallon. A sign showed up 'imr' on the panel, took the vehicle to dealer. He told imr battery needs to be replaced and will cost me $2800. Car is only 5 years old. I feel it`S a rip off by Honda. They should compensate.

- St.Louis, MO, USA

Battery loses charge suddenly and power is significantly lost to the point where acceleration is not possible. This has created several unsafe driving condition in highway and expressway entrances, as I can not get in safely or maintain safe speed during driving. This incident has repeated many times in the past three years. Battery indicator drops to zero bar or one bar and power is lost significantly.

- Yorba Linda, CA, USA

The contact owns a 2007 Honda Civic hybrid. The contact stated while driving up a hill, the vehicle began to hesitate and the rpms increased. The vehicle was not taken to the dealer for diagnostic testing. The manufacturer was not made aware of the failure. The vehicle was not repaired. The failure and current mileage was 60,000. The consumer stated the issue involves lack of power and acceleration. Which was caused by a software update issued by Honda. Honda is having an issue with the batteries dying prematurely. The update that was installed turned off the assisting electric motor to save the battery. Thus, resulting in lower miles per gallon and the lack of power and acceleration. Updated 10/03/11

- Brockton , PA, USA