Can You Drive a Hybrid in Extremely Cold or Hot Weather?by Sam Packer
The technology used by hybrid vehicles is able to do a lot just as well as, if not better than, conventional vehicles. A climate that reaches extreme temperatures, however, has the potential to decrease fuel efficiency. While a hybrid will almost certainly drive in extremely cold and hot weather, it is far less certain that it will consume fuel at the rates it should.
Hybrid vehicles, the common name most often used to refer to hybrid electric vehicles (HEVs), rely upon the combination of an internal combustion engine (ICE) and an electric motor. A computer in the car determines how much of the car's propulsion comes from the ICE and how much comes from the electric motor. The electric motor is attached to a set of nickel metal hydride batteries that collect and store energy before passing it along, at the computer's command, to be used to propel the electric motor and in turn the vehicle. These batteries are the most influenced by extreme temperatures.
Weather and Hybrids
While experts claim that hybrids will operate at temperatures ranging from minus 22 to 140 degrees F, the climate you live in is still the most important consideration when it comes to figuring out whether or not your hybrid will perform at its best in that location. In colder weather, gas mileage is diminished by about 10 to 20 percent in any vehicle, but that difference is more noticeable in a hybrid. In warmer weather, the vehicle needs to exert more energy to cool its machinery, which also lowers gas mileage. Thus, a hybrid may experience lower-than-expected gas mileage in an area that is generally colder or warmer than other areas.
Causes in the Cold
It should not come as a surprise that cold weather can impact a hybrid's fuel efficiency. As noted, winter temperatures affect fuel efficiency for all vehicles. When driving in colder weather, several energy-consuming systems are used in addition to an engine, such as heaters, defrosters, headlights and windshield wipers. Diminished resistance on roads and lower pressure in tires also lead to traveling shorter distances consuming the same amount of fuel needed to travel longer distances in warmer weather. Hybrids, however, involve some additional concerns. Due to the way they are built, they are not able to modulate their battery temperature as well, causing them to take longer to reach ideal operating temperature if starting from an extreme cold temperature. The longer it takes for the battery pack to reach its most efficient temperature, the longer the car's computer depends upon the ICE, thereby consuming more gasoline. In cold weather, therefore, the computer takes longer to make the switch to using the electric motor. The Honda Civic Hybrid, for example, does not allow itself to switch completely over to electric power, even at low speeds, at temperatures below freezing.
Causes in the Heat
In extremely hot weather, a similar problem exists. The engines and battery packs of hybrids require more energy than other vehicles to modulate their temperature. In hot weather, this means that a hybrid has to exert more energy on cooling, and it takes longer for its electric motor to reach the ideal temperature and provide its share of propulsion. Once again, relying more on the ICE diminishes gas mileage at higher temperatures.
Driving a hybrid in extreme temperatures will not mean the end of the car in most circumstances. This was the case in isolated incidents, however, when limits were stretched. A Toyota Prius in Barrow, Alaska, was reported to have a frozen battery pack at minus 56 degrees F.
While it is difficult to protect a vehicle completely from the elements it drives through, it is possible to help your hybrid out a little bit when in a climate that reaches extreme temperatures. Parking your hybrid in a garage will allow the vehicle's machinery to stay closer to its ideal operating temperature. So when you start your hybrid, it will take it less time to reach the temperature at which it runs most efficiently.
- shawnigan.snow storm.jan.2005.50.jpg image by Quidam Blackrose from Fotolia.com