It's not that straightforward!
Testing the effect of both methods (windows down, AC off versus windows up and AC on) has been done and debated by several different organizations. One of the leading groups, the Society of Automotive Engineers, conducted a number of tests on the effects of AC versus windows rolled down on automobiles.night driving
The SAE found that running an air conditioner in an automobile decreased gas mileage by 5 to 10%. Stanford University and SAE both recommend driving with your car’s windows down if you are traveling on city streets. However, when on a freeway or highway, the drag produced by your windows being rolled down exceeds the efficiency drop by keeping windows rolled up and AC on. Both organizations recommend that you use your car’s AC when driving at speeds above 45 MPH.
If you also have a car with low power then I find there is a noticeable difference in performance with the aircon on.
Regardless, it does make sense to run the aircon once a month for a short while else its seals can dry out.
Testing the effect of both methods (windows down, AC off versus windows up and AC on) has been done and debated by several different organizations. One of the leading groups, the Society of Automotive Engineers, conducted a number of tests on the effects of AC versus windows rolled down on automobiles.night driving
The SAE found that running an air conditioner in an automobile decreased gas mileage by 5 to 10%. Stanford University and SAE both recommend driving with your car’s windows down if you are traveling on city streets. However, when on a freeway or highway, the drag produced by your windows being rolled down exceeds the efficiency drop by keeping windows rolled up and AC on. Both organizations recommend that you use your car’s AC when driving at speeds above 45 MPH.
If you also have a car with low power then I find there is a noticeable difference in performance with the aircon on.
Regardless, it does make sense to run the aircon once a month for a short while else its seals can dry out.