Is the cost of using your car AC worth it when you could simply roll down your windows for free?
There is a school of thought that claims your car AC is a huge drain on your car engine and that it has a noticeable effect on your fuel usage. Another group claims that car air-conditioning is actually very efficient and that the drag caused by open windows is a larger detriment, especially on the highway. So, how much does the AC affect gas mileage as opposed to open windows, and what factors do you actually have to consider when making the calculations?
As is to be expected, there are documented advantages and drawbacks to either choice. To be able to weigh the two properly, you need to know the pros and cons of using air-conditioning or climate control.
Then there's the alternative. Sometimes, you don't need a high-tech solution to a problem, when a more analog one can do the same job. Still, there are reasons we create technology to perform seemingly mundane tasks, so what's actually good and bad about driving with the windows down?
If your car has been standing in the sun for hours and feels like a sauna when you get in, try the following:
Luckily, there have been multiple studies on this particular subject, so there is a fair amount of data corroborating the findings. Using your air-conditioning uses more gas than opening your windows, especially in city traffic or when driving slowly. At speed, open windows' added drag plays an increasingly important role, but it still wastes less fuel than using the air con. So, how much gas does the AC use? Up to 25% more, especially on short trips. So in the battle of air-conditioning up vs windows down, open windows are better for fuel economy.
What is the moral of the story? Open your windows whenever you can and only use your air-conditioning when you have no other choice, such as on the open road, when nothing else cools you down, or in dusty conditions. This is the best way to save fuel while still enjoying the benefits of air-conditioning when you need it, as permanently leaving the air-conditioning on wastes gas.
Use it mainly on the highway, where it is inconvenient and noisy to drive with open windows. To save fuel, drive with open windows whenever possible. However, it is still necessary to turn it on every week or two, even if just for a few moments. This helps keep the seals lubricated and prevents the system from developing premature leaks.
Chances are good that your cabin filter is blocked and should be replaced. Other possible causes for low flow include frozen evaporator coils or leaky/blocked air ducts.
There should be a light glow from the AC button. Climate-control systems should show a snowflake icon or something similar to indicate when the air-conditioner is running. It should have an override, too, to switch it off. You will obviously also feel cool air from the vents.
ACs use refrigerant gas, yes, and over time pressurized systems like this can begin to leak. Symptoms of a potential refrigerant leak include warm air blowing from the vents or a thin, greasy substance leaking around the compressor. First check for leaks before simply refilling with gas.