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Think Turning Off A/C In Your Car And Opening Your Windows Saves Fuel - Think Again!

WARRENDALE, Pa., Aug. 5, 2015 -

Members of the SAE International Interior Climate Control Standards Committee authored an article discussing fuel consumption. The choice involves your and your passenger’s comfort. There are many factors that impact how much fuel is used, including the specific vehicle fuel use (MPG rating) for the type of driving and the temperature and humidity conditions.


Consumers continue to be concerned about the fuel consumption of their vehicles. Many are not aware of the impact of accessories on this fuel consumption. Vehicle air conditioning (A/C) is one of the highest energy consuming accessories and has become standard equipment for vehicles.


The energy required to provide comfort in a vehicle depends on many factors such as the load on the A/C system is a function of the fan setting, the outside ambient and humidity, and the speed of the vehicle among other variables. The fuel consumption of the A/C will vary greatly depending on the weather conditions that prevail in a given area and also on the traffic patterns that are typical of a given city.


Comparing the use of a vehicle A/C system to a home air conditioning system may help consumers to understand why vehicle A/C can have such a large impact on fuel consumption. Consumers expect the vehicle A/C system to provide nearly instant relief after a hot soak in the summer sun. Home air conditioning usually runs continuously during the day, even if it may be set back at times to save energy. The demand and expectations of the consumer of the vehicle air conditioning system to provide comfort and maintain driver’s alertness may require increasing the system cooling capacity resulting in larger energy demands.


Depending upon many factors, the energy requirements when operating or shutting off the A/C system and opening the vehicle’s windows could be very similar.


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