Max A/C vs. A/C

[FloridaState]

Is there any difference between the "Max A/C" setting and just "A/C"? I don't really feel a difference at all. Would just the plain A/C setting save gas or anything?

I usually always just have it on Max since I live in Florida, but I was wondering today if just putting it on normal A/C would save gas or otherwise effect the performance.

Anyone?

 

[Joe Dirt]

A/C brings in outside air, Max A/C recirculates the existing cool air. Good to run on normal to dry the system out, especially when you're getting ready to shut the truck off- prevents musty smells from developing.

Neither will cost you more gas, and it's not worth the loss of comfort vs. what you gain by turning it off. The systems are pretty efficient. It will get cooler on max as you're not cooling hot air constantly, you're recirculating cooled air.

 

[ranger7ltr]

There is another position besides Max A/C???

Here it was over 100+ around 2 pm today and I love the fact that my interior cools down pretty quickly...

Seriously, I went from heat in Feb to max a/c in March and I don't change the setting until maybe October...

I do spray some Lysol into the defrost vents every 6 months though just to cut down the mildew possibility...This is an alternative to Joes' solution which, BTW, is what Ford recommends doing to keep the moisture down in the system...

 

[Joe Dirt]

Lysol smells nice too...

 

[FloridaState]

A/C brings in outside air, Max A/C recirculates the existing cool air. Good to run on normal to dry the system out, especially when you're getting ready to shut the truck off- prevents musty smells from developing.

Neither will cost you more gas, and it's not worth the loss of comfort vs. what you gain by turning it off. The systems are pretty efficient. It will get cooler on max as you're not cooling hot air constantly, you're recirculating cooled air.

Ahh, I see! Thanks.
Yeah I would never, EVER consider turning off the air in 95+ degree Florida just to save a few bucks. Sometimes at night, if it's not too muggy, I'll ride with the windows down around town, but that's because sometimes I get cold with the AC on.

Also, is turning off the AC a good thing to do every time you turn the truck off? I guess it's just habit, but as soon as a throw it in park, I turn off the AC, then turn off the truck. Would this help, hurt, do nothing or what? lol

 

[briwayjones]

Actually I think technically on Max it's supposed to be a little more efficient since it doesn't have to work as hard to cool the air. Max A/C actually stands for Maximum Efficiency not Maximum temperature as most people think. Whether it actually is more efficient I don't know.

Personally I turn mine off when I shut off my truck. I don't like it on when I turn the Explorer on. I like to let the truck warm up slightly before I turn it on. Whether it actually makes any kind of measurable difference on wear on the truck or AC, probably not.

 

[Joe Dirt]

It is slightly more efficient since you're cooling the already cooled air vs. cooling hot air over and over...

 

[FloridaState]

Thanks for the responses, guys. Yeah I don't know if turning off the AC before turning off the car does anything or not. It's just a habit.

 

[Maniak]

I'm pretty sure that when in max a/c it also turns on the heater bypass so hot water isn't in the heater core which also helps it cool the air more (or at least do it more efficiently)

~Mark

 

[Tbars4]

...Maximum A/C is an Efficiency mode and as mentioned before, it recirculates the cabin air..

...Maximum A/C setting will also not steal power from your motor for the A/C but, will steal the a/c from your motor under load...

...Using this setting and going up a hill or heavier than normal throttle such as passing, the motor will keep most of it's power while the A/C will be running but not cooling until you resume normal acceleration...

...You will use less fuel using Maximum A/C over A/C mode...

 

[briwayjones]

Normal mode will not turn the compressor off under engine load like Max AC does? Is that what you mean?

 

[Tbars4]

...Yes, and there are a couple other features to be aware of Between these settings..

...Maximum A/C actually cools the cabin better as it is recirculating already cooled air rather than drawing in warm/hot air and having to cool it...

From the Ford Explorer factory service manual under "System Airflow Description"

NOTE: No temperature modulation is possible in the MAX A/C position." Meaning the air temperature control dial will not adjust the air temperature in MAX A/C mode. If the air is too cold in MAX A/C then switch to normal A/C and then control the temperature with the air temperature control dial as needed.

On newer Explorers (there is a TSB for older explorers) when you have the AC set to "MAX AC" it actually redirects the hot water that usually goes through the heater core... This will in effect disable any heating functions...

 

[briwayjones]

Hmm, guess that's why trying to adjust the temperature wasn't working on my 2000 Explorer. I thought something was wrong with it. However it does adjust the temperature on my 2003 Sport on Max. (I never use anything but Max)

 

[97sprt4x4]

I have read somewhere and it was reaffirmed by my uncle that it's not very good for the motor to start with the AC on so when you turn the vehicle off you're supposed to shut the AC off so that when you start up it doesn't harm any of the components or put any extra strain on them. I heard it from my uncle, but it could just be an old mechanic's tale.

Justin

 

[Maniak]

I have read somewhere and it was reaffirmed by my uncle that it's not very good for the motor to start with the AC on so when you turn the vehicle off you're supposed to shut the AC off so that when you start up it doesn't harm any of the components or put any extra strain on them. I heard it from my uncle, but it could just be an old mechanic's tale.

Justin

Most newer vehicles don't turn on the compressor right away (including 1st gen explorers). That means you can leave the a/c in the on position when you start. Older vehicles would have the compressor on as the vehicle was started so you were supposed to turn it off before you restarted.

~Mark

 

[FloridaState]

Thanks for all the input, guys! Very helpful.

And thanks Tbars, I now know why my heat sucks on the occasion that I use it. I always have it on MAX. I just chalked it up to it hardly ever being used in Florida and wasn't really concerned about it.

 

[Tbars4]

...I'm glad to be of help...:biggthump

...I thought I would throw this link in here for another very common second gen A/C problem, for future readers...
http://www.explorerforum.com/forums/showthread.php?t=192842

 

[damarble]

Here's the real truth behind "Max A/C" haha!

The Four Goldberg Brothers
The four Goldberg brothers, Lowell, Norman, Hiram, and Max, invented and developed the first automobile air-conditioner. On July 17, 1946, the temperature in Detroit was 97 degrees.

The four brothers walked into old man Henry Ford's office and sweet-talked his secretary into telling him that four gentlemen were there with the most exciting innovation in the auto industry since the electric starter.

Henry was curious and invited them into his office. They refused and instead asked that he come out to the parking lot to their car.

They persuaded him to get into the car, which was about 130 degrees, turned on the air conditioner, and cooled the car off immediately.

The old man got very excited and invited them back to the office, where he offered them $3 million for the patent.

The brothers refused, saying they would settle for $2 million, but they wanted the recognition by having a label, 'The Goldberg Air-Conditioner,' on the dashboard of each car in which it was installed.

Now old man Ford was more than just a little anti-Semitic, and there was no way he was going to put the Goldberg's name on two million Fords.

They haggled back and forth for about two hours and finally agreed on $4 million and that just their first names would be shown.

And so to this day, all Ford air conditioners show -- Low, Norm, Hi, and Max -- on the controls. And, that's the truth....