Is there now a consensus on AC On vs Windows Down to save MPG

I would think the consensus where I live would be who cares. That AC needs to be on full time.
 
Yes,

The consensus is that one should either stop smoking or switch away from soda/beer to water l and drive with the windows up and AC on.
 
At higher speeds the drag from windows down actually can lose more gas mileage than the AC on uses.

Difference is minor enough do what ever makes you most comfortable though.
 
On the 3 cars I drive '97 Ford Escort wagon, '02 Ford Escort sedan, and '16 Nissan Versa sedan at speeds up to about 55 MPH it seems I usually get at least 10% better mileage with the windows down. I like the fresh air so until the temperatures get into the 90's with high humidity I usually leave the a/c off. I check mileage with every tank so I know what does and doesn't have large impacts on my mileage.
 
Originally Posted by BMWTurboDzl
Yes,

The consensus is that one should either stop smoking or switch away from soda/beer to water l and drive with the windows up and AC on.

I drink close to a gallon and half of water a day. But I'm still drinking my ginger ale a day.

Plus when the temp is 100F+ in April I'm using the AC.
 
Originally Posted by Bud
I would think the consensus where I live would be who cares. That AC needs to be on full time.


Yep, if heat and humidity are not enough for the passengers … dust and humidity are not good for the interior …
And then there are pollens and so forth …
 
Originally Posted by FordMan59
On the 3 cars I drive '97 Ford Escort wagon, '02 Ford Escort sedan, and '16 Nissan Versa sedan at speeds up to about 55 MPH it seems I usually get at least 10% better mileage with the windows down. I like the fresh air so until the temperatures get into the 90's with high humidity I usually leave the a/c off. I check mileage with every tank so I know what does and doesn't have large impacts on my mileage.

I can buy this. It probably varies from car to car. Model A might be 60mph, Model B might be 45.

I also wonder if interior volume matters. A car with really good aerodynmics but a really large interior space might do better with windows down to a higher speed than something with a small interior and poor aero.
 
I have to chuckle because I heard one of my friends say it was better to drive with the A/C than windows down for fuel economy when traveling at highway speeds back in 1980. Seems it would even more true today with modern A/C compressors and HVAC systems in cars. Either way, my windows are almost always up. It's quieter and calmer and cleaner.
 
Originally Posted by Leo99
I have to chuckle because I heard one of my friends say it was better to drive with the A/C than windows down for fuel economy when traveling at highway speeds back in 1980. Seems it would even more true today with modern A/C compressors and HVAC systems in cars. Either way, my windows are almost always up. It's quieter and calmer and cleaner.

Back then those ac compressors took a lot to run. Todays compressors don't take much hp.
 
In a Truck, it probably doesn't matter due to horrific aerodynamics and large frontal area ( moronic style concessions to fake joe construction guy) , but on a slippery car on the interstate or rural highway over 50 MPH I would say windows up AC ON for sure.

But if you can put your windows down at low speeds it likely not that hot out.

Up here inthe North Eaast, I only use AC for cooling in the car maybe 2 or 3 times a year when it goes well over 90.

But I'm living in nice rural, treed and hilly country; not on some fake, urban, 5 lane pavement ribbon full of worthless chain stores and
stop light every 100 yards. I would mentally "loose it" if I was forced to live somewhere like that.

You know, like Naples Florida or Scottsdale AZ - in town.

What are you thinking, Town planners?

$$$$$$ Wins again - you loose.
 
I typically own convertibles and enjoy open air driving on non convertible cars. There is no question that on the vehicles I've owned, MPG is improved with the AC compressor off, even at high speeds.

Ford and many others often run the compressor even when you think they don't. On these vehicles, the MPG/compressor test is may be skewed by not understanding that the compressor is still on. The only way to be sure it's off is to select the climate control system completely off.
 
The first ACs would run all the time they were switched on I believe. Add hot air to get to desired temp. (I think). New ACs cycle.

Does anyone remember the car AC kits you could buy from JC Whitney to add AC to your car? Of course without a bigger radiator they would overheat.
 
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Originally Posted by knerml
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Who did that measurement? Temperature in C (about 86F for us Canadian-degree-challenged), road speed in kph (80kph = 50mph) and fuel consumption in... gallons per mile.

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Who cares? In the ATL, it's run the A/C full blast from mid-May until October 1st (at least) anyways. This reminds me of people that worry about fuel mileage when buying a full sized pickup as a daily driver.
 
Originally Posted by supton
Who did that measurement? Temperature in C (about 86F for us Canadian-degree-challenged), road speed in kph (80kph = 50mph) and fuel consumption in... gallons per mile.

21.gif


GM
 
I've never seen any instances where using the AC reduces MPG by more than 1-2 MPG so call me wasteful (money, fuel, environmentally-unfriendly), I'm using the AC. I've had to use the AC at 7am when it's only 65º F outside but the humidity was horrible.

Besides, I've found that most modern cars, at least those with any half-decent amount of aerodynamics, aren't enjoyable with the windows down, at least when you get over ~40 mph or so. The wind noise, the ear-thumping buffeting, and the turbulence just aren't nice.
 
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