Posted by: Chris Maloney | July 11, 2012

Which is More Fuel Efficient, Air Conditioner Or Windows Down? It Depends On Speed.

English: Series of air conditioners at UNC-CH.

English: Series of air conditioners at UNC-CH. (Photo credit: Wikipedia)

I must thank bankrate for doing all the research for me.

If you’re traveling about in the heat, chances are you wonder how to save gas without slow broiling in your car.  So which is it?  Air conditioning or windows down?

Turns out, it really does matter how fast you are going.

At speeds below 40 mph, having the windows down means you are saving fuel despite the drag from the air coming in the windows.  This is especially true for stop and go traffic.

If you are one of the few people who still drive between 40 and 55, the results are about equal.

At highway speeds of 55 plus, the drag from the wind can be more than 20%, higher than the 10% loss from air conditioning.  A recent consumer reports study may have found this wasn’t an issue, but I’m going with bankrate on this one.

Fans win hands down, because they really don’t lower fuel economy.  So keep your windows rolled up and the fans on high at highway speeds.  Otherwise, windows down in traffic.

Earthgarage has a note about older cars.  Their air conditioners are less fuel efficient and will put more pressure on the gas efficiency.


Tell me what you think!

Please log in using one of these methods to post your comment: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s


%d bloggers like this: