Gas Performance of AC vs Drag - Page 2 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Rafael205 · 07-02-2013, 08:54 AM

Quote:

Originally Posted by snymat68

I think they concluded that below ~45mph it's better to keep windows down and ac off. Above 45 they said ac on and windows up is more efficient. But I think the results were so negligible it was easily within the statistical error margin, ie do what ever you want.

That sounds about right.. I've heard that the trade off point should be at about 50mph.. Assuming moderate wind conditions... Having your windows down at those speeds will create a lot of drag. At highway speeds the vehicle is strictly focusing on breaking wind resistance..

mwynn05 · 07-02-2013, 09:37 AM

I live in Texas, my ac will be on.

ZED SLED · 07-02-2013, 10:46 AM

All I know is that no matter what, after about 260 miles, I'd better be finding a gas station.

JohnnyBfromPeoria · 07-02-2013, 11:34 AM

In Phoenix this time of year, windows up-a/c off = death. Windows down-a/c off just means a slower death.

John B.

steveo9043 · 07-02-2013, 11:47 AM

I drive often for work and trips. I have noticed that windows up/down ac on/off doesn't make the biggest difference.

The biggest difference I have noticed is 63/68 seems to be the sweet spot (for me at least) I have averaged over 24mpg at those speeds with A/C on or off. I usually drive 73-80 on trips and i will average about 21 that way.

I think windows down at highway speeds does effect the MPG but in all honesty it might effect it 1mpg or about 16 miles when I fill up. (I never have put more then 17 gallons in filling up)

crateish · 07-02-2013, 11:58 AM

I'll say it again. I was shocked by the lack of wind entering the cabin under 50 mph. A pleasant surprise after I picked her up. My bet is that the effect with windows down is fairly negligible.

cjcamaro10 · 07-02-2013, 12:07 PM

Mythbusters debunked it. They did a test that showed almost no difference at all on a pick up.

Posted from Camaro5.com App for Android

Taintedveins · 07-02-2013, 12:14 PM

Highway miles windows down a/c off I have averaged a higher mpg than with a/c on, until recently I hadn't touched my a/c but with temps above 110 things are changing.

BBQdDude · 07-02-2013, 12:59 PM

Google Mythbusters, they went through this. Their outcome was it was a draw.

Jonster · 07-02-2013, 01:16 PM

Quote:

Originally Posted by BBQdDude

Google Mythbusters, they went through this. Their outcome was it was a draw.

Mythbusters didnt address 3 of my concerns:
1- A camaro and not a random car
2- Convertible tops
3- Back window drag

vroomapunk · 07-02-2013, 01:22 PM

You dont have to do some extensive test over time.

On a flat road, cruise control on, reset your MPG with the a/c off. Drive for a few miles, 2-5 miles should be enough, write down the number.

Turn the A/C on, reset MPG, and drive the same distance.

There you go.

Ive done this, and having the A/C on made a small difference

Jonster · 07-02-2013, 01:25 PM

Quote:

Originally Posted by vroomapunk

You dont have to do some extensive test over time.

On a flat road, cruise control on, reset your MPG with the a/c off. Drive for a few miles, 2-5 miles should be enough, write down the number.

Turn the A/C on, reset MPG, and drive the same distance.

There you go.

Ive done this, and having the A/C on made a small difference

You are correct I can test the windows vs AC, but not my convertible questions with coupe vs convertible.

Jonster · 07-02-2013, 02:31 PM

Quote:

Originally Posted by Comrando

Why?

I would imagine top down wouldn't be nearly as much drag as windows open and the air being trapped against the back window.

Do you care?

yes, I care. And I was asking the community if they had knowledge on the subject not opinions.

buckeyemike · 07-02-2013, 04:08 PM

I can't believe this is even an argument right now.

07-02-2013, 10:46 AM	#17
ZED SLED Drives: 2017 Mosaic Bk ZL1 M6 Join Date: Jul 2009 Location: South of Raleigh, NC Posts: 9,477 View My Garage	All I know is that no matter what, after about 260 miles, I'd better be finding a gas station. __________________

07-02-2013, 11:34 AM	#18
JohnnyBfromPeoria Drives: 2012 LS M6, Black Join Date: May 2009 Location: Phoenix, AZ Posts: 2,045	In Phoenix this time of year, windows up-a/c off = death. Windows down-a/c off just means a slower death. John B. __________________ 12 LS M6, IPF S/C, ASA GT-5 wheels, VMax PTB 1995 Mitsubishi Montero SR 1987 Dodge Raider Turbo Project 1986 Mitsubishi Montero 2.4l FI Transplant

07-02-2013, 11:47 AM	#19
steveo9043 Drives: 2012 45th AE 2SS Coupe Join Date: Sep 2011 Location: Chicago IL Posts: 1,125	I drive often for work and trips. I have noticed that windows up/down ac on/off doesn't make the biggest difference. The biggest difference I have noticed is 63/68 seems to be the sweet spot (for me at least) I have averaged over 24mpg at those speeds with A/C on or off. I usually drive 73-80 on trips and i will average about 21 that way. I think windows down at highway speeds does effect the MPG but in all honesty it might effect it 1mpg or about 16 miles when I fill up. (I never have put more then 17 gallons in filling up) __________________ 2012 45th L99 SS-Cold air inductions CAI-Dynatech LT's-Solo mach XL catback 333hp/341tq (before LT's)

07-02-2013, 11:58 AM	#20
crateish Drives: 45th Anniversary 2LT/RS Coupe Join Date: Sep 2011 Location: Pennsylvania Posts: 534	I'll say it again. I was shocked by the lack of wind entering the cabin under 50 mph. A pleasant surprise after I picked her up. My bet is that the effect with windows down is fairly negligible. __________________

07-02-2013, 12:14 PM	#22
Taintedveins Shark attack! Drives: 2011 Camaro LS Join Date: Nov 2010 Location: Tucson, AZ Posts: 1,561 View My Garage	Highway miles windows down a/c off I have averaged a higher mpg than with a/c on, until recently I hadn't touched my a/c but with temps above 110 things are changing. __________________

07-02-2013, 09:37 AM	#16
mwynn05 Drives: 2010 Camaro SS, Silver Join Date: May 2012 Location: Kingwood Posts: 2	I live in Texas, my ac will be on.

07-02-2013, 12:07 PM	#21
cjcamaro10 Drives: 2010 LS 6M Join Date: Jan 2013 Location: Lombard Posts: 184	Mythbusters debunked it. They did a test that showed almost no difference at all on a pick up. Posted from Camaro5.com App for Android

07-02-2013, 12:59 PM	#23
BBQdDude Drives: 2010 Chevy Camaro 2SS RS Join Date: Jun 2011 Location: Columbus, Oh Posts: 347	Google Mythbusters, they went through this. Their outcome was it was a draw.

07-02-2013, 01:22 PM	#25
vroomapunk [COTW 5/12/14] Drives: 2012 CRT NF Cammed 2SS/RS For Sale Join Date: Oct 2011 Location: NOLA Posts: 6,115 View My Garage	You dont have to do some extensive test over time. On a flat road, cruise control on, reset your MPG with the a/c off. Drive for a few miles, 2-5 miles should be enough, write down the number. Turn the A/C on, reset MPG, and drive the same distance. There you go. Ive done this, and having the A/C on made a small difference __________________

07-02-2013, 04:08 PM	#28
buckeyemike Drives: 2012 Camaro LS Join Date: Sep 2012 Location: Scott AFB Posts: 597	I can't believe this is even an argument right now.