Myth Busters look at open window vs air-conditioning

hdrygas · 06-05-2005, 04:10 PM

I recently saw Myth Busters and they were testing gas milage with air-conditioning vs. open windows. Now the test may not exactly apply to Prius drivers. They used identical Ford Explorers in the test. Put in a known amount of gas and drove at 55 on a track. The air was apparently set at max air because they were complaining it was too cold. The Ford with the open windows did a number of laps after the one on are conked out. Now the Explorer has the drag coefficient of a brick and the air is belt driven on the Engine but it was interesting none the less. I wonder how a test with Prii would have gone other than the obvious running out of gas is a bad idea?

**Tideland Prius** · 06-05-2005, 04:42 PM

I remember that episode. I think their verdict was that opening the window was more efficient. HOWEVER, note that they did the test at 45mph which is not even highway speed.

hdrygas · 06-05-2005, 06:27 PM

I thought it was 55 not highway but near. They complained about holding the car on the track. An Explorer is not exactly an Indy car! They are rerunning it in a half hour I will check it out. Did I mention that I think those guys have the greatest job in the world?

rflagg · 06-05-2005, 06:30 PM

55 was the first test, 45 was the second test.

My problem with their tests - and usually they're quite good at testing all possibilities - is that speed is an important factor. If say, they tested two cars at 90 mph, one with windows down, the other with the a/c, I'd bet good money there'd be quite an advantage for the a/c car.

However, of course, we all know this doesn't apply to the Prius since we know the windows down are more efficient up until about 45mph or so.

-m.

jayman · 06-05-2005, 06:51 PM

I thought it was an Expedition?

It was interesting how they used a dealer scantool to see how much fuel they were using, and even driving gently those things only got around 12 MPG, A/C or no A/C.

Jamie and Adam then theorized the scantool was for some reason a poor method to determine actual fuel consumption, so they did the measured amount of gasoline and drove until the things quit.

I agree, they have the best job in the world. Though I wonder if Adam and Jamie don't get on each others nerves? Usually if you combine a serious introverted guy (Jamie) with a comic extrovert (Adam) the sparks tend to fly.

Some of my more favorite comments from the show:

"KABOOM!"

"Am I missing an eyebrow ... ???"

Remember the ducks?

"Quack damn you!"

My absolute favorite, where Adam had to shave his entire body and was covered in gold paint. The part where they had the paramedic Sanjay do a rectal temperature probe:

"Oh Sanjay Sanjay .... will you still respect me in the morning?"

V8Cobrakid · 06-05-2005, 07:15 PM

well.. our A/C isn't belt driven. it doesn not rob HP which is worse than robbing electricity from our prius.

I said this in another post. With my AC on 72 degrees, i'm able to achieve 55 to 60 mpg on the highway. i can not achieve those numbers with my windows down.

The whole scenario switches under 45 or so. I consider 45 a city speed. I turn the A/C off and crack my windows.

skruse · 06-05-2005, 08:17 PM

At less than 45 mph: I set the AC at the coldest temperature. Select the maximum number of outlets (dash front and sides and floor). Turn the AC OFF. Open the two rear windows 10 to 15 cm. This results in good air flow through and reasonable cooling of the interior - even on warm days. No affect on fuel economy.

mikepaul · 06-05-2005, 08:20 PM

When the Today show was covering their 3-car convoy to show gas efficiency a week or so ago, they used the A/C-is-better-than-open-windows line.

Not sure this scenario will make them believe they were wrong...

V8Cobrakid · 06-05-2005, 09:45 PM

<div class='quotetop'>QUOTE(skruse\";p=\"95847)</div>

Quote:

At less than 45 mph: I set the AC at the coldest temperature. Select the maximum number of outlets (dash front and sides and floor). Turn the AC OFF. Open the two rear windows 10 to 15 cm. This results in good air flow through and reasonable cooling of the interior - even on warm days. No affect on fuel economy.
[/b]

i was wondering how to get better flow. i achieved it one day. i know the AC gets air pulled through it. bad windows work best though? hmm

DaveinOlyWA · 06-05-2005, 10:13 PM

i get good flow by cracking the rt front and left rear

06-05-2005, 04:10 PM	#1
hdrygas Senior Member Join Date: May 2004 Location: Olympia Wa Posts: 3,650 My Car: 2004 Prius Model: Package: #9 Thanks: 0 Thanked 2 Times in 2 Posts Friends: 0	Myth Busters look at open window vs air-conditioning I recently saw Myth Busters and they were testing gas milage with air-conditioning vs. open windows. Now the test may not exactly apply to Prius drivers. They used identical Ford Explorers in the test. Put in a known amount of gas and drove at 55 on a track. The air was apparently set at max air because they were complaining it was too cold. The Ford with the open windows did a number of laps after the one on are conked out. Now the Explorer has the drag coefficient of a brick and the air is belt driven on the Engine but it was interesting none the less. I wonder how a test with Prii would have gone other than the obvious running out of gas is a bad idea? __________________ Belle, a Millennium Silver '04 BC #9 "Becoming one with my Prius, ICE on ICE off" Belle has been passed on to my daughter. I have a new silver Prius 08. No name yet we have just met but not been introduced.

06-05-2005, 06:27 PM	#3
hdrygas Senior Member Join Date: May 2004 Location: Olympia Wa Posts: 3,650 My Car: 2004 Prius Model: Package: #9 Thanks: 0 Thanked 2 Times in 2 Posts Friends: 0	Re: Myth Busters look at open window vs air-conditioning I thought it was 55 not highway but near. They complained about holding the car on the track. An Explorer is not exactly an Indy car! They are rerunning it in a half hour I will check it out. Did I mention that I think those guys have the greatest job in the world?

06-05-2005, 06:51 PM	#5
jayman Senior Member Join Date: Oct 2004 Location: Winnipeg Manitoba Posts: 11,560 My Car: 2004 Prius Model: Package: B Thanks: 35 Thanked 185 Times in 168 Posts Friends: 12	Re: Myth Busters look at open window vs air-conditioning I thought it was an Expedition? It was interesting how they used a dealer scantool to see how much fuel they were using, and even driving gently those things only got around 12 MPG, A/C or no A/C. Jamie and Adam then theorized the scantool was for some reason a poor method to determine actual fuel consumption, so they did the measured amount of gasoline and drove until the things quit. I agree, they have the best job in the world. Though I wonder if Adam and Jamie don't get on each others nerves? Usually if you combine a serious introverted guy (Jamie) with a comic extrovert (Adam) the sparks tend to fly. Some of my more favorite comments from the show: "KABOOM!" "Am I missing an eyebrow ... ???" Remember the ducks? "Quack damn you!" My absolute favorite, where Adam had to shave his entire body and was covered in gold paint. The part where they had the paramedic Sanjay do a rectal temperature probe: "Oh Sanjay Sanjay .... will you still respect me in the morning?"

06-05-2005, 08:17 PM	#7
skruse Senior Member Join Date: Apr 2004 Location: Great Central Valley, Fresno, CA Posts: 1,206 My Car: 2007 Prius Model: Package: #6 Touring Thanks: 6 Thanked 1 Time in 1 Post Friends: 2	Re: Myth Busters look at open window vs air-conditioning At less than 45 mph: I set the AC at the coldest temperature. Select the maximum number of outlets (dash front and sides and floor). Turn the AC OFF. Open the two rear windows 10 to 15 cm. This results in good air flow through and reasonable cooling of the interior - even on warm days. No affect on fuel economy.

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06-05-2005, 04:42 PM	#2
Tideland Prius Moderator of the North Join Date: Oct 2004 Location: Canada Posts: 19,616 My Car: 2010 Prius Model: N/A Package: Technology Package (Canada) Thanks: 228 Thanked 344 Times in 243 Posts Friends: 23	I remember that episode. I think their verdict was that opening the window was more efficient. HOWEVER, note that they did the test at 45mph which is not even highway speed.

06-05-2005, 06:30 PM	#4
rflagg Join Date: Jan 2004 Location: Springfield, VA Posts: 946 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	55 was the first test, 45 was the second test. My problem with their tests - and usually they're quite good at testing all possibilities - is that speed is an important factor. If say, they tested two cars at 90 mph, one with windows down, the other with the a/c, I'd bet good money there'd be quite an advantage for the a/c car. However, of course, we all know this doesn't apply to the Prius since we know the windows down are more efficient up until about 45mph or so. -m.

06-05-2005, 07:15 PM	#6
V8Cobrakid Senior Member Join Date: Jun 2004 Location: hell Posts: 2,894 My Car: 2004 Prius Model: N/A Package: #9 Thanks: 9 Thanked 18 Times in 18 Posts Friends: 5	well.. our A/C isn't belt driven. it doesn not rob HP which is worse than robbing electricity from our prius. I said this in another post. With my AC on 72 degrees, i'm able to achieve 55 to 60 mpg on the highway. i can not achieve those numbers with my windows down. The whole scenario switches under 45 or so. I consider 45 a city speed. I turn the A/C off and crack my windows.

06-05-2005, 08:20 PM	#8
mikepaul Senior Member Join Date: Dec 2003 Location: Columbia, SC Posts: 1,742 My Car: 2004 Prius Model: Package: #9 Thanks: 1 Thanked 2 Times in 2 Posts Friends: 0	When the Today show was covering their 3-car convoy to show gas efficiency a week or so ago, they used the A/C-is-better-than-open-windows line. Not sure this scenario will make them believe they were wrong...

06-05-2005, 10:13 PM	#10
DaveinOlyWA 3rd Time was Solariffic!! Join Date: Apr 2004 Location: South Puget Sound, WA Posts: 12,378 My Car: 2010 Prius Model: IV Package: Solar Roof Thanks: 24 Thanked 121 Times in 103 Posts Friends: 10	i get good flow by cracking the rt front and left rear