Air conditioner and saving gas

[Aisling]

I was talking to my brother about gas prices, and car airconditioning came up. I said I was going to try not to use the AC as much this summer as I know it's a big gas burner. But he said more gas is burned with the windows open, as it causes friction and makes the car work harder.

Any opinions on this?

 

[disneymomto5]

I just read yesterday (I can't remember where), that if you're on the highway it's better to use the air conditioning because it has to do with aerodynamics, but if you're just running around town it's better to leave the windows open. Guess I'll be roasting this summer......

 

[Wildflowerz]

Er, I think they did a Mysthbusters on this. I think they found that there was either no difference or that it was better to use the A/C. I'll see if I can find it and post the link.

 

[fkj2]

I've read the same opinion as your brother.

It might have been more fuel efficient to open your windows when air conditioners were a new option in cars but the aerodynamic drag is worse now that technology for A/C has improved.

 

[mousecraszy]

Just ringing in here...but they just did this on the Today show Tuesday morning...the answer given was to run the air conditioning as the drag on the car with the windows down makes it less aerodynamic thus decreasing your car's efficiency...that's what their "green expert" reported!!

 

[girli565]

I was watching the Today show yesterday and they did a segment about saving gas in your your car. The host asked about the AC, and the expert said that when you open your windows it creates a drag and therefore uses more gas. AC uses more gas too so I guess if I had to choose I would use the AC. But I live in Miami where normal summer heat is in the high 90's so I always use the AC.

Whoops, it was Tuesday's show...

 

[Golf4food]

Mythbusters did indeed run this test. They ran it on a full size SUV and a smaller communter car. The results?

Up to around 45 mph it is better to not use the A/C and roll down the windows because the speed is not high enough to create adverse drag from the open windows yet.

Anything above around 45 mph starts to create more drag and at that point it becomes more economical to use the A/C and roll up the windows.

So there you go.

 

[Aisling]

Wow I was ready to bet the dog that he was wrong! I've never heard of this before.

Thanks for the replies!

 

[Wildflowerz]

K, I finally found it. Here's the link:

http://kwc.org/mythbusters/2004/11/mythbusters_boom_lift_catapult.html

They found that it's better to just run the AC.

 

[Aisling]

Reading the link now.

 

[Todd&Copper]

Search on the snopes website:

www.snopes.com

I believe there is info there regarding this and other "gas saving" measures and how well they work. If I remember correctly, there was a particular mph at which it switched from being better to have the windows open to better to have the ac on, but I could be remembering something incorrectly, since I haven't read this stuff since last spring when gas prices first hopped over $3.

 

[mickeyfan2]

Your brother is correct.

Newer cars are designed to have the least amount of drag with the windows closed.

BTW How did the talk with your DH got?

 

[dopeyfanatic]

I've read numerous reports that say driving around town, windows down. Driving freeway, a/c on. Driving around town there isn't enough "drag" to affect your gas mileage as much as the a/c does.

 

[Aisling]

Your brother is correct.

Newer cars are designed to have the least amount of drag with the windows closed.

BTW How did the talk with your DH got?

Geez, I was afraid someone was going to ask.

I started out jokingly about it, like honey, guess what I did?

It went ok, he was surprised it was so much more than I let him believe. He wasn't angry, or even disappointed in me. He was just STRONGLY focusing on Do you have it under control? Are you sure? Are you still charging? Are you fixing it? over and over and over again. I think I made him too worried to feel anything else. But I was prepared with all the bill statements and the paydown budget. I told him I was sorry, that I didn't want him to be disappointed in me, that I wanted him to trust me that I can still handle the finances without getting us into this mess again. I just wanted him to feel ok, and not worried. I'm sort of sorry I told him, though. He doesn't need this to worry about.
Every week, as I pay down, I'm going to be upbeat about it, "see honey, it's getting better", not dwelling on it, just taking care of it.

Thanks for asking!

But now do you see that I can't afford to be wasting gas!!!!!!!!!!!!!!!