Personally, I think when I open my roof and the windows it’s cheaper. Or maybe it’s just more fun, so the cost isn’t as important.
The chicken coop that was on our place had a hatch in the roof that could be opened to let the heat out in the summertime. If it’s good enough for the chickens, it ought to be good enough for us.
Now THAT is cheaper than AC!
The chicken coop that was on our place had a hatch in the roof that could be opened to let the heat out in the summertime. If it’s good enough for the chickens, it ought to be good enough for us.
Maybe YOU enjoy having your head and feet chopped off, having every hair plucked off your body, being gutted, then deep fried, and served with rice or potatoes, but I certainly don’t.
Not everything that’s good enough for the chickens is good enough for SOME of us.
BC.
Mmmmmmmmmmm, now THAT sounds appetizing. My mouth is watering…
You?ve taken a legitimate discussion about air conditioning vs. windows down and it?s effect on gas mileage and turned it towards hair pulling and frying humans like chickens.
Tread carefully, or turak2 will jump all over you for being complicit in the ?dumbing down of America.?
I started the thread and it looks fine to me. Now I need to get back tp preening my feathers.
Edward
“It doesn’t matter.”
In much of the country an A/C is not a luxury, its a life support system. MPG doesn’t matter if you are dead.
This is a rather old discussion but it confirms my aged recollection that Tom and Ray said it was more economical to use the AC at highway speeds rather than rolling the windows down.
I’m reading a four months old Parade magazine (July 18, 2021) Q&A by (the smartest woman in the world) Marilyn vos Savant, and she says better mileage with AC off, period. I question this because I still trust Tom and Ray, at least when it comes to now old cars.
I also think AC should be used when it’s more comfortable anyway. I typically don’t exercise in my car so sweaty clothes or the smell of perspiration ain’t a good thing.
Sweet Marilyn did not mention the high cost of gas (Tom would turn over in his grave). Perhaps she’s concerned about the environment. Even Tom and Ray would have me change my oil less often than I do. But they liked their automatics and AC.
No disrespect to Ms vos Savant but my son is a Mensa member, has a Genius IQ and trust me on this …never confuse Ability to Learn with Learning or Common Sense.
A good kid but there’s been times when I wondered what Turnip Truck he fell out of. 
Correct! (10 character minimum)
She sometimes wades into stuff that requires a quantitative analysis, which she doesn’t do. A few years ago she supplied the wrong answer to a question about the time needed to empty a reservoir. I emailed her the correct answer, she replied that she didn’t want to get into that much detail.
Back to the topic at hand. On an economy car with a small 4-cylinder engine, both the performance and the fuel economy suffer noticeably when the A/C is running.
Currently, I have a 2002 Daewoo Lanos, 2000 Chevrolet Silverado, and 2004 Corolla. Using the A/C in the Daewoo or the Corolla results in a noticeable reduction in performance and in fuel economy. On the truck, with a V-8 engine, running the A/C does not seem to affect the performance or fuel economy (which isn’t that great to begin with).
I have never kept track of mileage with windows opened or closed, If I want the widows open I will do it, if I want ac on and windows open I will do it, care not about saving 2 mpg, though in my experience no significant difference. Sure I keep up with the flow of traffic, 80 mph in a 70 mph zone and still get good for our car gas mileage. I do not worry about a couple of extra bucks at fill time, save more than that by brewing my own coffee for the trip instead of buying starbucks.
AC off windows up will absolutely get you better MPG at highway speeds vs windows down or AC on. That said, I’m not driving in my car at 70 MPH+ with the windows up and no air if it’s over 85 outside…If you’d rather not end up looking like you came out of a sweat lodge, then AC windows up is better at highway speed than windows down no AC.
Florida resident… AC on nearly 100% of the time.
Do not care to test the assertion that windows down, AC off gives better mpgs than AC on, windows up. Just No.
You don’t need the AC. When it’s raining cats and dogs.
Yes, you do… when those cats and dogs are SWEAT-TEE, the air is 97.5% humidity and it is still 95 degrees outside.
Hot and Wet still begs for AC! 
It’s not a matter of common sense. This is testable. No guessing to see which gives you the best gas mileage.
Not all cars have the same aerodynamics. Some vehicles may get better gas mileage with AC on and others with windows down. It also depends on the speed. There’s a lot of parameters that it’s impossible to give a correct answer that applies to all vehicles in all situations.
I get 24mpg or sohighway whether the windows are open or closed and ac is on and windows open. Anecdotal for sure but it is all I have for 500 mile road trips. fill up at beginning and at end, calculate mpg. sure sometimes 23, but too many fudge factors to consider it significant. Makes it about a gallon of gas for 500 miles. the 24mpg is a usual cruising speed of 77 to 80 mph
Cools it down for a short while. I’m not thinking of a light rain, but a gully buster that I’ve seen in Central Florida. Mostly, it was a joke though. Who would want their windows open in the rain anyway?