Air Conditioning: Facts, Fictions and Fuel Economy

The belief is that in order to conserve gas you should cut off your air conditioner and roll the windows down. This has been passed down throughout the years and many people swear by this rule and never use their air conditioning unless absolutely necessary. The question remains however is there any proof that this really occurs or is this belief simply untrue?...

Well the truth is that driving with your car windows down and the air conditioner off does have a positive effect on fuel consumption, but there is more to it than that. When you use the air conditioner in your car it does burn fuel but it depends on where you are driving and how fast you are going. In most cities where stop and go traffic is the norm you do save more fuel by letting your windows down if you are going 40mph or slower. You can save about 10% of your fuel consumption, which with gas prices being so high that can lead to be a considerable amount of savings. So when taking quick trips to the grocery store or picking your kids up from school it may be a good idea to leave those windows down if you are trying to conserve fuel.

But it gets a little more complicated. In certain conditions the air conditioner actually helps you save gas. Stick with me and I will explain this to you. The air conditioner saves gas by eliminating the air drag that is caused by the windows being down. This rule of thumb applies to driving on the highway or over 45 mph which is possible sometimes even within the city limits. It is a good practice to not drive at higher speed with the windows down because it can reduce fuel consumption by 20%. Different vehicles however are affected differently, for example SUV’s generally have a great air drag when the window is down so it is especially important to take note of this fact if you drive an SUV.

However there are a few things that you can do that may help to cool your car down and perhaps save you some gas. If you have a garage, parking in may help your car be cooler when you get in. You can also purchase windshield shades and they might help to. This makes since because the hot sun is not bearing down on your seats which can be especially important in the summer if you have leather. Some people get in and roll down their windows, to let some of the heat escape, before turning on their air conditioner. That is a good rule of thumb because it allows the hot air to blow out of the vents faster.

All air conditioning and heating systems come equipped with a fan. Using the fan even at maximum speed does not affect the overall fuel economy of your car. Circulating the cooler air inside of the vehicle instead of taking in the hot air from outside could help your car to cool down quicker. The main thing to consider when thinking about your air conditioner is the speed you are traveling. Some people don’t care about the fuel they burn and would rather use their air conditioner. Other people would prefer to keep those few extra miles so it is a good idea to adapt ways of cooling your car down naturally without the use of your car’s air conditioning. So the debate will continue but actually there is truth to both sides of the gas and air conditioner debate. However it is important to remember to pay attention to your speed and the size of the vehicle you are driving.