Auburn Hills, Michigan – Driving with the air conditioning on its more fuel-efficient than opening the windows, according to automotive supplier Delphi Thermal Systems.

“It is more fuel-efficient to drive with the air conditioning on than with the a/c off and the windows rolled down,” said James Bertrand, president of Delphi Thermal Systems. “That’s because a car uses less fuel to run an air conditioning system than it will use due to the aerodynamic drag on a vehicle when its windows are open.”

Delphi offers the follow tips for using an a/c system more efficiently:

– When entering a vehicle that has been sitting in the sun, fully open the windows to purge hot air, then close them and let the air conditioning cool the passenger compartment.

– Press the recirculation button, which may be labelled “Max,” to recirculate the cabin air back through the air conditioner. This will significantly reduce the energy used by the system.

– For a manual system, it is most efficient to keep the temperature control at the coldest position, and use the blower fan setting to adjust the amount of cooling. Adjust the temperature control only after the blower is at its lowest setting.

– If the a/c is not as cold as it used to be, have an air conditioning specialist evaluate and repair the system. It is normal for the system to lose small amounts of refrigerant by permeation through the hoses after years of use.

– The vehicle’s HVAC system may have an air filter that is clogged with debris and is reducing airflow. On newer vehicles, it could be located behind the glovebox or below the windshield wipers. Check the owner’s manual for instructions, or have service personnel change the filter. The service interval should be in the owner’s manual.

– Park in a shady spot, use a reflective sun shade, or leave the window partially open during sunny days.

Connect with Autos.ca