air conditioning / fuel consumption

[Seraphitia102]

This may be a rather odd and stupid question but does anyone know for sure that the higher I set my air conditioning inside my car, the more fuel goes to waste? I usually leave my A/C on the middle (2 tabs over) but was wondering if my A/C compressor actually works harder while all the way at the max. It's hot here in California.

 

[DropTopPony]

i get 3mpg less when i am using the air compared to no air windows down during local driving...now on the highway with the air on low i get the same mpg as i do with the windows down.

I would assume working the compressor harder will take more power and eat more gas theoretically.

 

[Kilgore Trout]

There was a thread on this the other day and SVTTech said that max and regular a/c used the same amount of fuel. Only difference was that the max setting is a "recirculate" mode and regular a/c draws in outside air.

 

[Stang|ess]

she was asking if it takes the compressor more effort to run at the max setting (notch 4), compared to a lower setting (notches 1-3).

 

[Kilgore Trout]

Oh, no I do not think so.

 

[SaleenGT2001]

no, that just changes how much resistance the blower motor recieves

 

[Kilgore Trout]

Read her post carefully, she is asking about max vs regular a/c not blower fan speed.

 

[Stang|ess]

Read her post carefully, she is asking about max vs regular a/c not blower fan speed.

Read it again, she's asking what I mentioned in my frist post

 

[Kilgore Trout]

Seriphita will tell us the answer...

Off topic, she has some serious coinage in her mustang

 

[Stang|ess]

Seriphita will tell us the answer...

Off topic, she has some serious coinage in her mustang

I KNOW! She could have bought a blower, but I guess she prefers aesthetics first.

Anyways, let me break it down for you Killy.

blahblah I usually leave my A/C on the middle (2 tabs over)I leave my AC on tab #2
but was wondering if my A/C compressor actually works harder while all the way at the max.If I turn it on the max (tab) will the compressor work harder? blahblah

You have to read the 2 lines together to understand what she's asking.


I'm going to be extremely embarassed if it turns out that I'm wrong

 

[Stang|ess]

She's gonna come back to see her thread has quite a few replies and be disappointed when it turns out no one answered her question

 

[Mustang5L5]

Fuel use is the same no matter what setting it is on.

On Defrost, the compressor cycles more but with the A/C on it runs near continuously. Doesn't really matter what position the fan blower speed is in or if it's in Normal or MAx.

The difference between Normal and Max is that Normal takes outside air and cools it while MAX takes it from inside. Max is cooler since it is cooling air that has already been cooled. Normal is better for starting up since outside air is usually cooler than air sitting inside a car for some time in the hot sun. Also Normal may be better at nighttime or when the temp is just warm or it's slightly humid. Normal will also cause more dripping of water from under the car.

 

[Kilgore Trout]

She's gonna come back to see her thread has quite a few replies and be disappointed when it turns out no one answered her question

I answered her question based on my interpretation in post #3

SaleenGT2001 answered her question based on your interpretation in post #6

 

[mransr]

Fuel use is the same no matter what setting it is on.

On Defrost, the compressor cycles more but with the A/C on it runs near continuously. Doesn't really matter what position the fan blower speed is in or if it's in Normal or MAx.

The difference between Normal and Max is that Normal takes outside air and cools it while MAX takes it from inside. Max is cooler since it is cooling air that has already been cooled. Normal is better for starting up since outside air is usually cooler than air sitting inside a car for some time in the hot sun. Also Normal may be better at nighttime or when the temp is just warm or it's slightly humid. Normal will also cause more dripping of water from under the car.

+1

 

[Seraphitia102]

She's gonna come back to see her thread has quite a few replies and be disappointed when it turns out no one answered her question

HAHA I just wanted to know if I am working my compressor "not as hard" on notch level 2 as opposed to 4.

But thanks for all your efforts, and yes I guess I'm "coinage" in which I assume from what you guys wrote, it's spending more money on the outside than the inside.

Well yes, like most girls, looks are the most important. Performance will only get me to the next red light maybe 1-3 seconds faster, big deal. I rather look bitchin on the way over.

As for even more "coinage," I am getting a Saleen rear seat delete with 2 amplifiers sitting on the left and right with a capacitor in the middle, a new Mach 2 hood, and 2 brand new Saleen Recaro leather seats.

I'll probably get a Vortech SQ blower in February 2008, when my certified pre-owned warranty from Ford ends.

 

[Mike97gt]

This may be a rather odd and stupid question but does anyone know for sure that the higher I set my air conditioning inside my car, the more fuel goes to waste? I usually leave my A/C on the middle (2 tabs over) but was wondering if my A/C compressor actually works harder while all the way at the max. It's hot here in California.

if it's over 80 degrees the A/C works LESS in the max position.. you will get better mileage because of this..

Max A/C uses recirculated a/c from inside the car instead of outside air.. since the inside air is cooler the system does not have to work as hard to cool the air.. Use this setting when it's above 80 degree or when the humidity is high.

if you use the blower fan on high the a/c will work slightly harder to keep the evap core temp around 40 degrees.. but the difference is small and you will not notcie any difference in MPG. So it's not worth suffering with the air hardly blowing out of the vents

 

[dude496]

umm....does anybody on here actually know how a/c works...and how an alternator works?

Max vs. low, will be about the same.

A/C vs. windows down....on a city street will be about the same...on the highway, A/C will give you better gas mileage (windows down creates drag....watch the myth busters episode if ya think im b/s'ng you)

 

[Mike97gt]

umm....does anybody on here actually know how a/c works...and how an alternator works?

Max vs. low, will be about the same.

A/C vs. windows down....on a city street will be about the same...on the highway, A/C will give you better gas mileage (windows down creates drag....watch the myth busters episode if ya think im b/s'ng you)

I think I know how a a/c system works I have years of background in fixing them and all the training ford offers on climate control systems done.

I am explaining how using max a/c setting on our cars switches to recirculated air, this allows the a/c system to cool already cooler interior air, this allows it to work less to keep the evap core temps at or near 40 degrees.

and yes you are right, windows up will give you better highway gas mileage. this is common knowledge, anybody with a clue as to how wind resistance effects engine load can understand that, and the amount of load the a/c system has on the motor is less than the load caused by the extra wind resistance, so you will get better highway mileage with the windows up and a/c on.. and even better mileage with the a/c off and windows up..

 

[the98stang]

umm....does anybody on here actually know how a/c works...and how an alternator works?

Max vs. low, will be about the same.

A/C vs. windows down....on a city street will be about the same...on the highway, A/C will give you better gas mileage (windows down creates drag....watch the myth busters episode if ya think im b/s'ng you)

WRONG

They proved on mythbusters that you get better mileage with the windows rolled DOWN versus using the AC.

 

[Susky]

What if I put the top down and run the A/C on max?