Does running the air conditioner in the car decrease gas efficiency? Significantly? By how much?

Question

I have a friend who refuses to run the AC even on rather hot days because she has been told - and seems to believe herself - that doing so decreases efficiency and makes her cost for gas higher. The car is a Volkswagen Jetta.

Answer 1

fact is the A/C compressor will add aditional load to the engine, Depending on how much you run it will affect your fuel efficiency. So your friend is right running the AC will cause the engine to burn more gas simply because it's working more. As for how much I woudl say a noticable amount.

Answer 2

This is tricky, It is commonly thought that running the AC can cause a decrease in gas mileage however, MYTHBUSTERS tv show disproved that myth. Believe that the reason for this myth is that when you run the AC, you are more comfortable when you drive, thus you are more prone to drive more often. When you get into the sauna that is your can, you want to get out as fast as possible, hence you drive less, so it appears that the tank of gas lasted longer. It is a FACT that driving with the windows down decreases your gas mileage by as much as 10%. So the final word is AC is better than windows down. Hope this helped.

Answer 3

For my vehicles, running the A/C has decreased fuel economy between 10%-20%. So for a $3.00 worth of gasoline, that means $0.30 - $0.60 per gallon is being used by the A/C. (This is for my specific vehicle, doing various tests and keeping track of fuel consumption)

People have made various claims, but the best way to test is to do the work yourself on your own vehicle. If your friend doesn't like using the A/C. Offer to pay for a full tank of gasoline with the condition that she use the A/C. I mean you paid for the gas. Ask her to see if she notices a drop in fuel economy, this way you can be comfortable and she doesn't have to worry about the cost.

Answer 4

yes, like our engineers always preach-- running the A/C while driving around the city is like adding 18-20% on fuel cost, 10-12% on hi-ways. this will also contribute in the wear and tear in your engines, esp that's a Volks, by 8-12% every year if A/C is continously ON. that's the very truth in it according to studies, BUT as what the sales guys like us are saying--- it's a part in buying a car. who wants to drive in hot days? you get sweaty, oily and it will just add you cost in cleaning,detailing your car interior-- wow! see, you do the math.. get as much worth from the car you bought-- enjoy the drive, the steering wheels, the looks, the sounds (music), all the accesories including the A/C.

Answer 5

In almost every car I have ever had, running the AC on high has decreased fuel mileage by half.

Answer 6

Not true...actually you waste the same amount of gas with the windows down....the air get trapped and pulls the car so you have to use more gas....if you roll up your window and use the A/C you use the same amount of gas...