A new report from the American Automobile Association (AAA) reveals extreme temperatures reduce efficiency and range while increasing operating costs for electric vehicles and hybrids. Testing was conducted on a chassis dynamometer—a device similar to a treadmill for cars—with the HVAC (heating, ventilation and air conditioning) systems set at 72°F inside the vehicles and laboratory test cell temperatures set at 20°F, 75°F and 95°F.Results from the hot-temperature (95°F) tests revealed hybrid vehicles experienced a 12.0 percent decrease in fuel efficiency, measured in miles per gallon (MPG). Additionally, EVs showed a 10.4 percent reduction in efficiency, measured in miles per gallon equivalent (MPGe), and an 8.5 percent loss in driving range compared with moderate temperatures (75°F).Results from the cold-temperature (20°F) tests revealed hybrids lost 22.8 percent in fuel economy. EVs also demonstrated a 35.6 percent drop in MPGe and a 39.0 percent decrease in calculated driving range.