Not Logged In Log In   Sign Up   Points Leaders
Follow Us    10:23 AM

Message Forum - Read Message

Category: Fuel Economy > Topics Add to favorite topics   Post new topicPost New Topic
Author Topic: Windows Open, No AC Back to Topics
GSDMan
Rookie Author
Maryland

Posts:27
Points:11,950
Joined:May 2013
Message Posted: Sep 12, 2013 9:19:24 AM

I didn't want to hijack another posters thread and I don't recall this being addressed.

I know about the drag of open windows at highway speeds versus running AC, blah, blah, blah. What I'm wondering is can we alter the airflow enough to mitigate the increased drag with the windows open? My Ram has a sliding rear window and I noted with it open it significantly calmed down the air currents inside the truck. Going on the premise that it takes energy to move air and it appears airflow through the truck is lessened, or at least less turbulent, with the rear window open, could I be getting better mpg this way?

I'm doing a mileage test with 91 octane and a ECM tune right now so I'll test this after that but I'm wondering if anyone's experimented along these lines?
REPLIES (newest first) Post a Reply
Awing1
Champion Author Ontario

Posts:1,897
Points:512,590
Joined:Aug 2013
Message Posted: Jun 17, 2014 7:39:54 AM

AC on the highway, window down in the city.
OilerFan
Champion Author Tulsa

Posts:16,984
Points:3,104,090
Joined:Aug 2005
Message Posted: Jun 17, 2014 7:13:50 AM

Yep. WHen it's almost 100 degrees in the sun, I'm using A/C.
Glasman
Champion Author South Carolina

Posts:12,602
Points:1,465,325
Joined:Nov 2006
Message Posted: Jun 17, 2014 6:53:40 AM

GSDman:::

going to be mid 90's here this week with a lot of humidity- I'll use my A/C
Mikeyl
Champion Author Cleveland

Posts:9,576
Points:1,980,115
Joined:Aug 2004
Message Posted: Jun 16, 2014 5:28:12 PM

You'll probably have to do a lot of studies to make your thesis valid.
rando991
Champion Author Missouri

Posts:1,700
Points:962,870
Joined:Jun 2011
Message Posted: Jun 16, 2014 9:19:02 AM

On a really hot day, I open my window as I get going to let out some of the extremely hot air, while running the AC, then close the windows and run AC on recirculate.
Madridjoe
All-Star Author Lancaster

Posts:529
Points:249,280
Joined:Jun 2007
Message Posted: Jun 16, 2014 6:35:07 AM

on a nice day, I prefer windows down for around town driving
hoopitup2000
Champion Author Virginia

Posts:2,091
Points:643,385
Joined:Jul 2013
Message Posted: Jun 16, 2014 6:33:01 AM

Windows open if moving & not too hot
Glasman
Champion Author South Carolina

Posts:12,602
Points:1,465,325
Joined:Nov 2006
Message Posted: Jun 16, 2014 5:54:44 AM

mid to high 90's with humidity here this week-

A/C on.
GLM4205
Champion Author Toledo

Posts:6,918
Points:1,484,510
Joined:Dec 2010
Message Posted: Jun 16, 2014 5:46:09 AM

I like the windows open unless real hot.
Jackson126
Champion Author Virginia

Posts:1,484
Points:454,845
Joined:May 2014
Message Posted: Jun 13, 2014 6:59:32 AM

I use my ac
pghbill
Champion Author Pittsburgh

Posts:2,644
Points:1,255,460
Joined:Jul 2005
Message Posted: Jun 12, 2014 1:00:04 PM

my ac is broke so I have no choice
Awing1
Champion Author Ontario

Posts:1,897
Points:512,590
Joined:Aug 2013
Message Posted: Jun 12, 2014 9:14:24 AM

Window open for the local or city road, AC for highway.
hoopitup2000
Champion Author Virginia

Posts:2,091
Points:643,385
Joined:Jul 2013
Message Posted: Jun 12, 2014 6:30:24 AM

I like the windows open unless real hot.
WilhamClouse
Champion Author Calgary

Posts:3,141
Points:789,210
Joined:Jun 2013
Message Posted: Jun 12, 2014 12:35:05 AM

AC all the way
mnrick041
Champion Author Twin Cities

Posts:18,528
Points:2,199,465
Joined:Jun 2009
Message Posted: Jun 11, 2014 9:16:32 PM

I prefer the AC rather than having windows down
Awing1
Champion Author Ontario

Posts:1,897
Points:512,590
Joined:Aug 2013
Message Posted: Apr 14, 2014 9:10:40 AM

I would use AC on the highway since it will create noise and resistance to go forward. MPG would be similar for both AC and opening window.
drgeeforce
Veteran Author Los Angeles

Posts:325
Points:433,495
Joined:Oct 2011
Message Posted: Apr 14, 2014 9:06:10 AM

Having windows up or down has neglible impact on MPG. The A/C does reduce MPG.
deant99
Champion Author Ontario

Posts:182,082
Points:574,890
Joined:Sep 2011
Message Posted: Apr 13, 2014 9:15:25 PM

AC on high way open rear windows in city
dgsteven
Champion Author Los Angeles

Posts:4,185
Points:1,017,125
Joined:Oct 2012
Message Posted: Dec 30, 2013 3:57:28 AM

A/C is better
PaylessKY
Champion Author Kentucky

Posts:12,120
Points:2,390,220
Joined:Oct 2008
Message Posted: Dec 28, 2013 10:23:18 AM

In the summer time I use the a/c.
DrThos
Sophomore Author Madison

Posts:180
Points:14,975
Joined:Feb 2012
Message Posted: Dec 25, 2013 4:07:28 PM

Top down a/c off, unless it is really hot then I will use the a/c and still keep the top down.
dallfo
Champion Author Denver

Posts:3,087
Points:652,695
Joined:Oct 2013
Message Posted: Dec 25, 2013 10:51:52 AM

Merry Christmas.
RS101
Champion Author Minnesota

Posts:16,220
Points:771,625
Joined:May 2013
Message Posted: Dec 25, 2013 9:13:37 AM

Merry Christmas
johnny81356
Veteran Author Nebraska

Posts:410
Points:74,495
Joined:Feb 2012
Message Posted: Dec 25, 2013 3:52:46 AM

I use ac most of the time in hot weather
twt
Champion Author Virginia Beach

Posts:14,092
Points:1,788,435
Joined:Mar 2005
Message Posted: Dec 25, 2013 2:41:39 AM

I just do whatever feels comfortable. I don't use a lot of heater or AC, so the difference in gas mileage, is minimal to me.
Maintroll
Champion Author Lexington

Posts:11,998
Points:2,513,385
Joined:Aug 2008
Message Posted: Dec 21, 2013 8:48:40 AM

I leave the air on year around only in winter I have the dial set to warm which in turn keeps the windows clear. Try it, you might like it. This is an old bus drivers trick in case you wondered.
probedjg2013
All-Star Author Louisville

Posts:881
Points:122,225
Joined:Oct 2013
Message Posted: Dec 19, 2013 7:55:07 AM

if it is hot out I always use my ac, but when I can leave my windows down I will always do that
Glasman
Champion Author South Carolina

Posts:12,602
Points:1,465,325
Joined:Nov 2006
Message Posted: Dec 19, 2013 2:38:27 AM

now you tell me the door glass is adjustable , well I'll be dipped.
pghbill
Champion Author Pittsburgh

Posts:2,644
Points:1,255,460
Joined:Jul 2005
Message Posted: Dec 18, 2013 12:59:41 AM

no way, ac all the time
carinthuist
Champion Author San Francisco

Posts:6,291
Points:1,063,725
Joined:Mar 2012
Message Posted: Dec 17, 2013 11:42:54 PM

vent only
BaieCRD
Champion Author New Jersey

Posts:1,720
Points:156,835
Joined:Nov 2013
Message Posted: Dec 17, 2013 6:04:56 PM

Prefer fresh air vs forced air
buddy_maynard
Sophomore Author Cincinnati

Posts:120
Points:739,805
Joined:Nov 2011
Message Posted: Dec 17, 2013 5:16:14 PM

I use the AC to keep my boys (4 and 2) cool.
RalphHightower
Champion Author South Carolina

Posts:6,787
Points:1,525,120
Joined:May 2011
Message Posted: Dec 17, 2013 5:57:57 AM

I use AC
randy3116
Champion Author Tennessee

Posts:1,738
Points:630,510
Joined:Oct 2012
Message Posted: Dec 16, 2013 11:26:30 AM

i prefer fresh air but will use a/c when temps rise over 85
davisadm
Champion Author Los Angeles

Posts:3,849
Points:1,224,050
Joined:Dec 2011
Message Posted: Dec 16, 2013 9:49:29 AM

I like it quiet, without wind buffeting when I drive. Windows will stay closed, a/c, air, or heat will be on as needed.
WEPSMAN
Champion Author South Dakota

Posts:11,527
Points:2,743,775
Joined:Mar 2005
Message Posted: Dec 16, 2013 9:08:36 AM

I would rather be comfortable than worry about saving a couple cents on gas.
herbiepopnecker
Champion Author British Columbia

Posts:16,491
Points:3,253,130
Joined:Sep 2005
Message Posted: Dec 9, 2013 1:01:11 AM

It's -20, I don't think I'll drive with the windows open....
Camry05
All-Star Author Indiana

Posts:734
Points:286,770
Joined:Apr 2012
Message Posted: Dec 8, 2013 7:05:30 PM

haven't done a mileage test that way, maybe something to send to the mythbusters
ny10
Champion Author Virginia

Posts:2,497
Points:913,545
Joined:Mar 2011
Message Posted: Dec 6, 2013 10:17:24 AM

In highway, I think it is better to use A/C than opening windows.
Lambang
Champion Author Illinois

Posts:2,779
Points:718,855
Joined:Aug 2013
Message Posted: Sep 18, 2013 2:33:26 PM

When it is hot out the AC is on and the windows are up.
Chazzer
Champion Author Nevada

Posts:18,911
Points:4,068,705
Joined:May 2002
Message Posted: Sep 18, 2013 1:47:08 PM

Widows open around town. Windows closed out the interstate w/AC on!
OceanArcher
Champion Author Mississippi

Posts:8,500
Points:1,999,995
Joined:May 2004
Message Posted: Sep 18, 2013 10:57:37 AM

Windows open, huh? That driver doesn't live where the "luv bugs" flourish ..
dvc2
Champion Author Oakland

Posts:3,391
Points:1,189,725
Joined:Aug 2011
Message Posted: Sep 16, 2013 1:42:02 AM

Closed with the air on.
OilerFan
Champion Author Tulsa

Posts:16,984
Points:3,104,090
Joined:Aug 2005
Message Posted: Sep 15, 2013 8:54:38 AM

In good weather, I drive with the windows down, except when at high speeds (too loud).
Bus936
Champion Author Lexington

Posts:19,831
Points:4,030,705
Joined:May 2004
Message Posted: Sep 15, 2013 8:18:21 AM

The vehicles most of the time run far more efficient with the AC on and there isn't that much difference in gas mileage. I run mine year around in order to keep the windows defogged in winter, except with the temperature on a warm setting.
Glasman
Champion Author South Carolina

Posts:12,602
Points:1,465,325
Joined:Nov 2006
Message Posted: Sep 15, 2013 7:51:18 AM

like to see you travel across Arizona & parts of New Mexico in August when the temps are triple digit without air.
lyanMI
Champion Author Detroit

Posts:1,729
Points:729,185
Joined:May 2012
Message Posted: Sep 14, 2013 7:20:53 PM

mostly AC
bluenvoy
Champion Author Nashville

Posts:17,387
Points:2,144,865
Joined:Oct 2005
Message Posted: Sep 14, 2013 9:37:08 AM

AC. Too much dirt gets in the car when I drive with the windows open.
Dustin19d
Champion Author Fayetteville

Posts:2,517
Points:885,660
Joined:Nov 2012
Message Posted: Sep 14, 2013 6:25:45 AM

I have a bone stock 93' Civic with 238K miles that averages 39.4 MPG over the 50K miles I have put on it. It has no AC so the windows are down 9-10 month out of the year. Not to bad considering the EPA rating is 29 city 36 highway. Windows up, windows down, AC on, AC off it doesn't matter. What matters is your location and how YOU drive.
sagnat
Champion Author Riverside

Posts:1,920
Points:1,023,205
Joined:Jun 2012
Message Posted: Sep 12, 2013 10:19:03 PM

If i am running at highway speed, as long as it isn't too hot I will put all four windows down about 3 inches and it doesn't seem to effect my MPG. At speed, windows down can create drag, while windows up leave basically a lick surface which gives better MPG even with the AC running.
MTK143
Veteran Author Pittsburgh

Posts:259
Points:88,635
Joined:Mar 2012
Message Posted: Sep 12, 2013 3:17:55 PM

windows
Post a reply Back to Topics