A/C or MAX A/C ?

Topic: A/C or MAX A/C ? (Read 1257 times) previous topic - next topic

A/C or MAX A/C ?

July 19, 2006, 11:35:31 PM

I guess this apply not only to fox cars. I guess this is all Ford Related. I heard about the use of the A/C actually is less economical than MAX A/C, because in MAX A/C the compresor sucks air from the cabin and its easier to cold than outside air, and that saves a little bit of gas, but i dont know if consumes the same amount of power from the engine. Since here in my town is nearly 35c-39c and that is HOT!, but driving the Suv or the F-150 with the AC on would skyrocket the gas bills. Which mode would be cheaper to use ?

A/C or MAX A/C ?

Reply #1 – July 19, 2006, 11:44:28 PM

I roll the windows down personaly

A/C or MAX A/C ?

Reply #2 – July 19, 2006, 11:54:56 PM

Max A/C recirculates so it is more efficient. Plus if you drive near decaying roadkill you won't suck in that smell.

A/C or MAX A/C ?

Reply #3 – July 20, 2006, 12:44:22 AM

When you first start the car use the normal A/C, because the outside air is cooler than the air inside the car. Once the air in the car starts to cool down, then switch it to MAX. I believe it says something to this effect in the owner's manual...

A/C or MAX A/C ?

Reply #4 – July 20, 2006, 01:04:24 AM

On a side note, Anyone know where I can get an 84' Manual?

A/C or MAX A/C ?

Reply #5 – July 20, 2006, 02:12:00 AM

I watched mythbuster and they did a compareison about windows down no A/C and window up with A/c windows up with A/c proved to be better on gas than windows down.

A/C or MAX A/C ?

Reply #6 – July 20, 2006, 10:20:23 AM

That Mythbusters was also with a new SUV, AC systems and engines have gotten more efficient over the years. With 20 year old vehicles it may still be better to roll down the windows.

A/C or MAX A/C ?

Reply #7 – July 20, 2006, 10:27:00 AM

Quote from: 84 Fila

On a side note, Anyone know where I can get an 84' Manual?

ebay

A/C or MAX A/C ?

Reply #8 – July 20, 2006, 10:28:58 AM

Quote from: wyoming_bird

That Mythbusters was also with a new SUV, AC systems and engines have gotten more efficient over the years. With 20 year old vehicles it may still be better to roll down the windows.

Not likely... Especially in a aero car that has much less drag than a SUV..

A/C or MAX A/C ?

Reply #9 – July 20, 2006, 10:48:46 AM

I would imagine it depends on the 20 year old vehicle you're referring to. With our cars, that are pretty much as aerodynamic as most modern cars, it's probably best to have the A/C on. With other 20 year old cars (Crown Vic, Caprice, GM G bodies, etc), where the air going over the car is so messed up that open windows won't affect it much, I'd imagine the A/C would burn more gas.

I would imagine the engine power also has a big impact. If you've got a Chevette with A/C the thing is gonna burn more gas because about half the engine's power is turning the compressor (ok, not half, but given the Chevette's limited power, a good percentage :D). A big, torquey 5.0, on the other hand, won't struggle to turn the compressor, so it won't use as much power.

This is pretty much the same reason a V6 'Bird will often get worse mileage than a V8 'Bird - the V6 may be smaller, but it's working harder to move the car. For a given speed (or acceleration rate) you're gonna have your right foot planted deeper with a V6 car. Where a V8 car just loafs along at 1500RPM at 70MPH, the V6 is gonna be breathing a little harder (hence the 3.27 gears compared to the V8's 2.73)

A/C or MAX A/C ?

Reply #10 – July 20, 2006, 10:54:04 AM

Quote from: ipsd

I watched mythbuster and they did a compareison about windows down no A/C and window up with A/c windows up with A/c proved to be better on gas than windows down.

They also followed up on that test on a later episode and explained that windows-down was more fuel efficient at low speeds.. say under 45.. and that A/C was more efficient above those speeds. Their initial test was done at a speed that was favorable for A/C.

A/C or MAX A/C ?

Reply #11 – July 20, 2006, 11:26:49 AM

Quote

Quote:
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Originally Posted by ipsd
I watched mythbuster and they did a compareison about windows down no A/C and window up with A/c windows up with A/c proved to be better on gas than windows down.

They also followed up on that test on a later episode and explained that windows-down was more fuel efficient at low speeds.. say under 45.. and that A/C was more efficient above those speeds. Their initial test was done at a speed that was favorable for A/C.

Thats a good point, I was just assuming low speed driving since I only use my Bird going to and from work where I dont get going any faster than 40. I guess I should have figured out whether we were talking about freeway or cross town before I chimed in. It doesnt do my milage any good to have the AC on while I sit at 4 stoplights for 10 minutes on my way home. Its much easier to just roll down the findows, and its windy enough here that I am always guaranteed a breeze.

A/C or MAX A/C ?

Reply #12 – July 20, 2006, 11:46:41 AM

When it is 100 outside + humidity...I don't care which is more efficient, I just want to be comfortable.

Anybody have a link to that Mythbusters episode? From what I've heard...they did a poor job with the A/C - windows myth.

A/C or MAX A/C ?

Reply #13 – July 20, 2006, 11:52:41 AM

I'll have to go through them later. I have most of the episodes.. err.. coughdownloadedcough.. :p

(I'd do it now, but I'm watching Top Gear) :p

EDIT: OK, I went through the intros of a bunch of them, and the first test was in season 2, episode 9. The follow-up to the test was in season 3, episode 1. According to the revisit, the crossover point is 50 mph.