Air conditioning or Climate Control help

MarkN

E92 wrote:

We dont really get the type of weather that makes aircon worthwhile in the summer, you need to go to somewhere a good bit hotter, where it is a life saver.

Jesus I have my car less than 19 degrees most of the whole year round!

Days like today, windows up, set on LO LO.. heaven. Couldn't do without now.. I'd even say I don't miss a sunroof when I have climate.

colm_mcm

E92 wrote:

In theory, it was possible to get a 1.6 Aura with chilled air before then, but most people(stupidly) chose the sunroof in lieu of Air Con.

Availibility had a lot to do with what people bought, Toyota brought in way more Auras with sunroof than they did with A/C

BostonB

E92 wrote:

....
A common belief is that airconuses more fuel, and it does when it is on. But opening windows uses a lot more fuel than many people think, especially at high speeds.

I still don't think having a window open is half as hard on fuel as AC. On my car when I turn on AC you can feel the drain on power immediately. Its like 4 people just got in the car. Opening the window at a speed doesn't have anything like the same effect. That said it usually too noisy to have the windows open at speed with todays streamlined shapes.

I used to like sunroofs, but after having a car with AC I prefer that. Especially in our damp climate for clearing the windows. Its great at cooling but my fuel economy takes a big hit.

colm_mcm

what's your car BostonB. I find it frains the power on some cars, and on others it doesn't seem to have an effect.

JoeA3

I've never noticed a power-drain in my cars with climate control switched on (A3 and VW Golf). I think I read someplace that newer systems are more efficient, in fact I think the VW's automatically "switches off" when it detects the driver accelerating rapidly.
That said, I remember driving my mother's Fiesta and there certainly was a drop in power when you turned on the A/C (or the radio:D)

Neither have I ever noticed any difference in fuel economy.

BostonB

Older 16v so all the power/torque is above 4k so thats probably why. As you say newer AC units probably need less power.

Stephen

The climate control in my car has no noticeable effect on power. I would think that at high speeds opening the window would be worse because of the extra drag it would cause.
I remember they tried to test this on mythbusters but they used big box-shaped gas-guzzling American SUV's driving around in circles to test it, rather than aerodynamically efficient vehicles.

BostonB

Stephen wrote:

The climate control in my car has no noticeable effect on power. I would think that at high speeds opening the window would be worse because of the extra drag it would cause.
I remember they tried to test this on mythbusters but they used big box-shaped gas-guzzling American SUV's driving around in circles to test it, rather than aerodynamically efficient vehicles.

Also using huge engines wouldn't be the same as our smaller engines. Still...

Windows down vs. air conditioning

"Urban puzzle": it is more efficient, on a hot day, to run with the A/C on and windows up than to run with windows down (b/c of increasing car's drag).

Computer-based mpg measurements:

* 11.7/11.8 with A/C on and windows up
* 11.7/11.8 with A/C off and windows up
* 11.3 with A/C off and windows down

So, according to the computer, it's better to use A/C with windows up.

This was too quick and easy for TV, so they decided to stage a seven hour marathon, race-til-you're-empty duel, with Jamie driving an SUV with A/C on and Adam driving an SUV with windows down. Though, once the safety inspector intervened, it was no longer a seven-hour marathon, it was a bit slower (45mph instead of 55mph), and a lot shorter (only 5 gallons each).

Jamie's A/C car ran out of gas first -- Adam's windows down SUV ran for another 30 laps -- completely contradicting the computer mpg estimate. Computer estimate based on air flow into the engine, so it would appear that it is unable to properly model the difference between A/C and windows down.

Mythbusted

30 laps is a lot longer because of no AC

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

Last time around, in "AC vs. Windows Down", the MythBusters concluded that using AC was more efficient than opening your windows to cool down. However, they quickly admit that they were wrong to make such a hasty confirmation. In fact, they find that over 50 mph, you're better off with your windows open your AC on, but slower than that, use the AC open your windows. Myth busted. (Yes, I heard them wrong. So sue me. -- Ed.)

http://www.tvsquad.com/2005/10/17/mythbusters-mythbusters-revisited/

I'd say it probably depends on the specific car, the type of journey and the style of driving.

Anan1

If Mythbusters used two vehicles then their results can be disregarded.