As local drivers prepare for colder weather, a study released earlier this year offers a useful warning for anyone considering an electric vehicle or hybrid: mild weather efficiency does not tell the whole story.

Winter planning needs to account for both the trip and the energy used to keep the vehicle and its occupants warm.

AAA’s May 1 study tested three electric vehicles and three hybrids at laboratory temperatures of 20, 75 and 95 degrees Fahrenheit. Cabin climate controls were set to 72 degrees. Researchers used a chassis dynamometer, equipment that allows a vehicle to operate under controlled conditions while remaining in the laboratory.

At 20 degrees, the electric vehicles averaged a 39 percent reduction in calculated driving range compared with the moderate temperature condition. The hybrids’ fuel economy declined 22.8 percent. Those findings describe the tested vehicles and conditions; they are not a promise that every vehicle will lose the same amount on every winter trip.

The distinction matters for shoppers reading an advertised range figure. A household should consider its longest routine trip, the opportunity to recharge and the extra driving that might arise unexpectedly. A vehicle that comfortably handles an ordinary commute may require a different plan for an extended trip on a cold day.

Federal fuel economy guidance explains several reasons winter consumes more energy. Cold engine oil and other fluids increase friction, and engines take longer to reach efficient operating temperatures. Colder air increases aerodynamic drag. Cabin heating and defrosting require energy, while lower temperatures can also affect batteries and regenerative braking.

For a hybrid, the gasoline engine provides flexibility, but its presence does not erase the seasonal penalty. Drivers comparing monthly fuel receipts should distinguish increased consumption from a change in gasoline prices. Recording miles traveled and gallons purchased provides a clearer picture than comparing two fill-up totals alone.

Charging location deserves equal attention for electric vehicles. AAA’s cost calculations used national energy prices from March 27, not current Logan County rates. Under those assumptions, cold weather operating costs differed substantially between home charging and public charging. The study’s dollar figures should therefore be treated as research estimates rather than a household budget.

An owner can build a more relevant estimate by checking the electricity rate on the home bill and the prices charged by stations they expect to use. A prospective buyer should also establish where charging will actually happen. Access to a driveway, an outlet or a nearby station does not automatically answer questions about charging speed and installation needs.

The federal guidance recommends combining errands to reduce repeated trips with a cold engine. For electric vehicles and plug-in hybrids, preheating the cabin while connected to a charger can preserve driving range.

Owners should use their vehicle’s instructions to understand available scheduling and temperature settings rather than assume every model operates identically, especially during longer winter journeys.

Energy savings should fit around safe operation. Clear windows and adequate visibility remain necessary, even when defrosting uses power. A useful winter plan provides enough energy for the conditions instead of depending on avoiding essential equipment. It also leaves room for a changed route or a longer trip than originally expected.

For local households, the most useful comparison is personal: the distance driven, the places available for charging and the demands of the coldest trips.

The AAA results offer a reason to ask better questions before buying and to review routines before winter. They do not require abandoning electric driving or assuming a hybrid is unaffected by temperature. A realistic seasonal plan starts with the actual vehicle and the journeys it must complete.