how much does air condition effect mpg?

[marcink99]

i have a 06 a4 qt and it makes me wonder since i menaged to get 30mpg on the highway with ac on at all times how much more would i get without ac?

Thanks in advance

[B6driver]

this goes along with the myth of windows up or windows down... windows up with AC vs windows down and no AC. its been tested, and the results are almost insignificant. dont worry

your looking at maybe +/- .5 mpg + the inconvenience of it all

[AudiWxGuy]

What about windows up with no A/C?

[Raymax_2.0t]

I'm pretty sure I've gotten 36mpg highway with AC on...

[EMAXX]

I picked up my car on the fourth of July in Denver, CO. It was 104F outside. I had the A/C cranked and still managed to get about 35mpg on the highway on the trip back.

[79%N1]

36 mpg?? was it all downhill?? if you reset your trip meter while you are already up to speed on the highway then the average is way wrong... dont fool yourself... it takes more gas to get up to 75mph than it does to sustain it...

I dont know about the mileage increase with no a/c on... but i did notice that the infamous 2.0T idle vibration is all from the A/C being on. If you hit the econ button when your are idling the vibration all goes away.

[Entropy333]

Normally I am an AC hater, in my g/f's older camry it rapes mpg. But I decided to splurge and run the AC the other day. I read about the syncros running smoother, and sure as shit...car shifts nicer w/ AC on. To be honest I didn't notice any drop in normal mileage for what I was doing.

[AudiWxGuy]

Entropy333....are you an engineer, physicist, meteorologist or chemist? I am a meteorologist and we had to learn tons about entropy and enthalpy in thermodynamics.

[Raymax_2.0t]

36 mpg?? was it all downhill?? if you reset your trip meter while you are already up to speed on the highway then the average is way wrong... dont fool yourself... it takes more gas to get up to 75mph than it does to sustain it...

Sorry, I was mistaken. That was instantaneous mpg, but I don't think the AC affects mpg a whole lot.

[AudiWxGuy]

I get 36 mpg from ATL to Macon on a consistent basis. It's about a 100 mile trip. And the elevation goes from 1200 feet to 400 feet. On the way up from Macon to ATL, I avg between 30-33 mpg. This is averaging a speed of 75-80 mph.

[Phrost]

I think it's around 50mph (we'll just say highway speeds) where it is more efficient to run your AC compared to having your windows down. But with all seriousness, running your AC in the worst case scenario will only make you get a couple less miles per gallon. The effect is minimal, and the dollar or so extra you'll have to pay for gas is worth it to keep your 100% comfortable in my opinion.

[CardNation]

http://dsc.discovery.com/fansites/my...thbusters.html

[ArmanB7]

Damn i get like 20mpg

[slingblade]

In the worst stop/go traffic (6 miles, average speed 15mph or so, over 35min) in Boston I was getting as low as 12mpg with the AC on if it was really hot/humid... That being down from 16-18mpg or so when it was hot/humid with no AC

[Entropy333]

Entropy333....are you an engineer, physicist, meteorologist or chemist? I am a meteorologist and we had to learn tons about entropy and enthalpy in thermodynamics.

I graduated with two degrees...Chemical Engineering and Chemistry. I currently work on the North Slope of Alaska for BP as a Site Engineer. Two weeks on, two weeks off and as much food as you can fathom. :)

~James

[quattshot]

Ask TOYOTA.

They are adding a solar panel and small motor to power the A/C Unit in there 2009-2010 PRIUS.

[JGreen76]

AC is priceless in FL...no need to keep track.