Fuel Efficiency: Use A/C or have windows down?

[krzyray]

When driving on the freeway (80mph), is it more fuel efficient to use air condition or does having both windows all the way down cause too much drag and end up making the car work harder thus use more gas?

[crusin by]

I've heard on the radio a while ago that its better to drive with the a/c on and the widows up. Will your alternator still use the juice if your a/c is not on? If so, I say blast the a/c all day.

Richard
97CamryXLEV6

[Guest]

maybe you could get some government funding and do a test for us

and just for fun find out what happens with the air on and the windows open

shoe

[krzyray]

maybe you could get some government funding and do a test for us

and just for fun find out what happens with the air on and the windows open

shoe

Think you're misinterpreting the question. I am trying to find out what uses less gas on the freeway driving at 80mph. Either using your A/C with windows UP. Or using no A/C and having both of your windows all the way down.

[onefiend]

maybe you could get some government funding and do a test for us

and just for fun find out what happens with the air on and the windows open

shoe

Think you're misinterpreting the question. I am trying to find out what uses less gas on the freeway driving at 80mph. Either using your A/C with windows UP. Or using no A/C and having both of your windows all the way down.

Some people just dont understand the meaning of "sarcasm" LOL

[austinsolara]

I heard somewhere recently that 40MPH is the tradeoff between windows down and A/C.

[fotodad]

maybe you could get some government funding and do a test for us

and just for fun find out what happens with the air on and the windows open

shoe

Think you're misinterpreting the question. I am trying to find out what uses less gas on the freeway driving at 80mph. Either using your A/C with windows UP. Or using no A/C and having both of your windows all the way down.

Some people just dont understand the meaning of "sarcasm" LOL

...or have a use for it in within this forum.

I think it's a legitimate question; one which I've often asked, as well.

[krzyray]

I heard somewhere recently that 40MPH is the tradeoff between windows down and A/C.

Yup you are right! I just finished a search in Google, and found this: http://www.reconnectingiowans.org/train ... ation2.htm

Use air-conditioning during higher-speed driving only (over 40 mph).

"Air conditioning can be your car's biggest summer energy use. However, at high speeds, air-conditioning actually wastes less energy than rolling down your windows; this is because a “smooth” car uses less energy to run the air conditioner than would be lost due to "drag" at higher speeds. Rather than running the air conditioner continuously, use the vent setting as much as possible. When you get to your destination, park in the shade to reduce the need for using the air conditioner."

[Fletch]

I got bored coming back from a 4 hour trip once...
I accelerated to 120 mph going uphill with the A/C on, windows closed much easier than I could on level ground, A/C off windows open. With windows open it just seemed to take forever to get from 110 to 120 mph.

[Guest]

sarcasum nothing if you really want to know fill up a tank at 2 am go out on the freeway windows closed no AC drive from 1 end of town to the other at what ever speed. for x amount of miles or kilometers.

THEN FILL UP YOUR TANK AGAIN

write down how much it cost when the depth stop kicked in

get back in your car and do the same run with your windows open at the same speed go back to the gas station fill up again and wrtie down the cost when the pump stops automatically ( depth stop)

now do the run 1 more time with your ac on and your windows up.


see the patern? if you really want to know find out for ur self? shouldnt take more than an hour

and like i said if you really want to have fun with this do the test with both the ac on the open window drag


shoe