Hybrids And Electric Cars In Cold Weather

You purchased a hybrid car because you wanted better fuel economy. But before you signed the check, you might not have asked many questions about hybrids and winter driving. Now the cold fronts have arrived, and you're wondering: How do frigid temperatures affect fuel economy? Should you change your driving habits in the cold? And come to think of it, how do you jump-start a hybrid?

Lower Temperatures Mean Lower Fuel Economy

Winter takes a toll on the mileage of hybrid and conventional vehicles alike. This is because the longer it takes for the vehicle's internal combustion engine to reach its normal operating temperature, the worse the emissions and mileage will be.

However, a hybrid is going to be more affected by cold than a conventional car. This is because a hybrid relies on a storage battery and a generator for part of its propulsion.

Batteries, like humans, are happiest in the 60-degree to 85-degree range. When temperatures drop below 40 degrees — and more so as temps drop further — the chemical process by which a battery stores energy slows. This means that a battery starting up in freezing temperatures will have less available power than it would on a 75-degree day. To offset the reduced battery power, the car uses the engine's gasoline component to power the vehicle, and doing so reduces its overall miles per gallon and range.

Keeping Your Battery Warm And Happy

The two main things you can do to improve a hybrid's efficiency in cold weather are to keep the car in a garage and to pre-warm or pre-condition the passenger compartment of the vehicle while it's still plugged into the charging station.

Keeping the vehicle in a garage will usually keep the batteries and passenger compartment warmer than if the vehicle were parked outside. A heated garage will help even more, although heating your garage may not be very energy efficient.

Also, many newer hybrids and electric vehicles have a feature that allows owners to run the passenger compartment heater while the car is plugged in, without depleting the charge in the vehicle propulsion battery pack. The same goes for pre-cooling the passenger compartment using the vehicle air-conditioning. In both cases, you can minimize the temperature's impact on the car's range by not depleting the propulsion charge and by maintaining the battery's optimal temperature.

Lastly, altering your driving style has a clear impact on mileage for both hybrid and conventional vehicles. Generally, smooth driving at posted speed limits will provide the best range and fuel economy. By maintaining consistent speeds and avoiding unnecessarily sharp accelerations, you can get the most from your vehicle energy expenses.

Jump-starting Your Hybrid

Hybrids are easy to jump. This is because almost all hybrids still use a conventional 12-volt battery in some part of their system. To get the hybrid's gasoline engine started, jump the 12-volt battery as you would in any other car. The other, high-voltage traction motor battery rarely becomes so depleted that the gasoline motor and generator can't charge it.

Whenever you jump-start a hybrid, be sure to follow the vehicle manufacturer's jump-start procedures. They can be found in the owner's/operator's manual, usually located in the vehicle's glove box. And if you have any questions about the procedure, call in a professional. You don't want to be poking around under the hood or in the high-voltage traction motor battery compartment unless you're a trained and qualified technician. If a part says "Don't Touch" or "Don't Take This Apart," then don't touch it or take it apart. There may be 500 volts inside.

Winter Driving Hazards

There's no reason to be apprehensive about driving a hybrid in the winter. Hybrid vehicles from mainstream manufacturers are all very well-engineered to meet, and usually exceed, government safety standards. If you're interested in government testing and vehicle safety information, safercar.gov can tell you how the car performs in a variety of emergency situations.