In terms of saving fuel, is it better to wind down the window or stick on the air conditioning when driving in hot weather?

I've always found it a delicious irony, given the greenhouse gas emissions that pour from their tailpipes, that many modern cars now boast in the showroom that they have "climate control" onboard. If only.

But it also reminds me how air conditioning has so quickly become a standard in our cars, whereas just a decade or more ago it was seen as something of a luxury. Something that, for many of us Brits, was deemed to be a very American sort of extra and, therefore, somewhat excessive. After all, what would we possibly want with air conditioning? On those rare British days when the car got too hot inside, you could just wind down the window to let in some of Mother Nature's own air-conditioning.

But now just about every model seems to have air conditioning as standard and, what's more, it's amazing how many people seem to drive around with it on regardless of the weather outside. We've become acclimatised to climate control.

It's a shame, as air conditioning significantly reduces a vehicle's fuel efficiency – by about 10% on average. But, then again, having the windows wound right down is clearly going to reduce the aerodynamic performance of any vehicle and therefore increase its fuel burn.

The general consensus of the car industry folk seems to be that the best environmental option is to use a wound-down window to cool your vehicle if you are travelling at speeds lower than 45mph. Once you go faster than that, air-conditioning becomes the better option, as driving in a car with a window down at speeds above 55mph can increase fuel burn by about 20%. Most of the industry refers to a 2004 study [pdf] by the Society of Automotive Engineers that looked into the issue.

Nice post. Thumbs up.

oh boy! adonbiliv it

DonBobes:
oh boy!
adonbiliv it

You need pics?

The additional work of pushing the compressor, powering the fans and blowers plus energy loss to heat will theoretically increase fuel consumption.

The extra drag created on a car with lowered windows during movement will also increase fuel consumption as the car has to battle harder to overcome the drag.

The equilibrium is getting to know when the air-conditioning consumes less than the added drag with lowered windows.

Putting all these into context, we should also remember that performance and economy are opposing parties in automobile design

Now to practical terms, I don't mind burning 'more' fuel on a sunny day to power my air-conditioning. I have also gotten accustomed to putting on the engine and AC even in a parking lot with no movement intended.

When switching on the AC, I think of comfort first before fuel consumption.

The extra fuel savings won't be enough to fund my campaign to be the next senator from my constituency so let me enjoy for the time being

Its a luxury bro, you've to get used to it.

ajaolu:

You need pics?

I don't need pics. I think fine art drawing will do..

I no send fuel consumption. I drive around with a/c no matter what? Except my gas has gone low.

ajaolu:
In terms of saving fuel, is it better to wind down the window or stick on the air conditioning when driving in hot weather?

I've always found it a delicious irony, given the greenhouse gas emissions that pour from their tailpipes, that many modern cars now boast in the showroom that they have "climate control" onboard. If only.

But it also reminds me how air conditioning has so quickly become a standard in our cars, whereas just a decade or more ago it was seen as something of a luxury. Something that, for many of us Brits, was deemed to be a very American sort of extra and, therefore, somewhat excessive. After all, what would we possibly want with air conditioning? On those rare British days when the car got too hot inside, you could just wind down the window to let in some of Mother Nature's own air-conditioning.

But now just about every model seems to have air conditioning as standard and, what's more, it's amazing how many people seem to drive around with it on regardless of the weather outside. We've become acclimatised to climate control.

It's a shame, as air conditioning significantly reduces a vehicle's fuel efficiency – by about 10% on average. But, then again, having the windows wound right down is clearly going to reduce the aerodynamic performance of any vehicle and therefore increase its fuel burn.

The general consensus of the car industry folk seems to be that the best environmental option is to use a wound-down window to cool your vehicle if you are travelling at speeds lower than 45mph. Once you go faster than that, air-conditioning becomes the better option, as driving in a car with a window down at speeds above 55mph can increase fuel burn by about 20%. Most of the industry refers to a 2004 study [pdf] by the Society of Automotive Engineers that looked into the issue.

Nice post. On the contrary, I trust Brits will need all the climate control their vehicle's got plus heated seats (if equipped) to make it through in winter!
Personally, I have no regards for saving fuel at the expense of not having AC. I just set the temp dial to condition the cabin.

Denn:
The additional work of pushing the compressor, powering the fans and blowers plus energy loss to...
The extra fuel savings won't be enough to fund my campaign to be the next senator from my constituency so let me enjoy for the time being

Nailed it!

Regardless of speed I most always drive with windows down. I only use AC if I'm making a call or at sustained high speed.

Forget fuel joor comfort first