Which is better ?AC ON or Windows rolled down in high speeds

prince1a · 16th June 2006, 09:33

Hi all,
I have somewhere read that on high speeds, if you roll the side windows down, it will affect mileage as the resistance caused by the air increases. How does this drop in mileage comparable to putting ON the AC at high speeds ?

burjiis · 16th June 2006, 10:05

Hi Prince,
I distinctly remember one of the Auto Magazines (I think Autocar) mentioning that the VTEC gave better fuel efficiency with the AC on at high speeds than with the AC off and the windows rolled down. So, if you own an OHC you got your answer. Would be interesting to know about other cars too.

Regards,
Burjis

ajmat · 16th June 2006, 10:17

High speed, windows down - like driving with a parachute

jkdas · 16th June 2006, 10:22

Quote:

Originally Posted by ajmat

High speed, windows down - like driving with a parachute

ther! couldnt put it better. With windows rolled up; teh car becomes more sleek/aerodynamic, and hence performance better wrt to mileage and kmph

iraghava · 16th June 2006, 10:24

Quote:

Originally Posted by jkdas

ther! couldnt put it better. With windows rolled up; teh car becomes more sleek/aerodynamic, and hence performance better wrt to mileage and kmph

And not to mention better Passenger comfort too

1100D · 16th June 2006, 10:28

How about Windows rolled up and AC off. Isn't that the best regarding FE?!

naveendhyani · 16th June 2006, 10:31

Quote:

Originally Posted by 1100D

How about Windows rolled up and AC off. Isn't that the best regarding FE?!

a/c is a "NEED" when its hot, so definitely the FE will improve when u have a/c off and windows rolled up.

kb100 · 16th June 2006, 10:36

nobrainer.. windows rolled up and AC running will give you more milage... and comfort!... wind noise/roar is a major factor in travel fatigue..

1100D · 16th June 2006, 11:02

Quote:

Originally Posted by naveendhyani

a/c is a "NEED" when its hot, so definitely the FE will improve when u have a/c off and windows rolled up.

Well the the "NEED" is sometimes relative. In a country where people choose an Alto Over Santro and a Santro over (say) Palio (although it has other reasons for not selling). NEEDs are somewhat dictated by the money rather than comfort and pleasure.

BTW Window rolled up and No AC is also the enthusiast's way of saying I have arrived! (But then his NEEDs are different)

k36 · 16th June 2006, 11:51

What a pity! ... on highways where there is little pollution... where you can enjoy the fresh air you need to keep the windows rolled up for the sake of mileage.
On the other hand in polluted environment of cities.. in the crawling traffic you need to keep windows rolled up ... and AC ON .. at the cost of mileage!

revharder · 16th June 2006, 14:37

AC ON and windows up and then driving at 'constant' high speed will give you really good fuel economy.
just try to visualise the scene ahead and try to maintain your speed accordingly.
our very old santro still gives us 17+ kmpl while cruising at abt 100-110kms on NH1 with AC ON for 100%. although being a breadbox design, windnoise do irritates a lot, but we have a thing called music system to take care of that noise!

varunroy · 16th June 2006, 15:58

Quote:

Originally Posted by 1100D

How about Windows rolled up and AC off. Isn't that the best regarding FE?!

AC off, Windows rolled up, Ingnition off, Vehicle locked = the best FE you can ever get.

You will suffocate to death man. And if you survive that you'll probably go to sleep because of low Oxygen and end up crashing someplace. At the end of a long journey there won't be YOU & YOURS.

So long....

1100D · 16th June 2006, 16:10

Quote:

Originally Posted by varunroy

AC off, Windows rolled up, Ingnition off, Vehicle locked = the best FE you can ever get.

You will suffocate to death man. And if you survive that you'll probably go to sleep because of low Oxygen and end up crashing someplace. At the end of a long journey there won't be YOU & YOURS.

So long....

Right you are.

But some people drive that way, not for FE considerations but something else.

On the other hand I had jokingly suggested this way of driving to some of my colleagues for good FE and guess what, THEY DO IT!! When the get out of their cars the whole world is AC! Surprisingly still they say my advice helps! As a by-product every ml of Sweat translates to some amount of adipose being lost.

Kaizer Sozay · 17th June 2006, 00:51

I am for AC on on along drive.
My Zen gave me an Avg of 19.5 on a drive Bombay to Goa with the AC on all the Way...

micraft · 17th June 2006, 15:14

[FONT=Arial]If a car moves at 80km/hr with windows rolled down, how much would it move at with the windows [/FONT][FONT=Arial]rolled up?[/FONT]
[FONT=Arial][/FONT]
[FONT=Arial]?[/FONT]
[FONT=Arial] [/FONT]

16th June 2006, 09:33	#1
prince1a Newbie Join Date: Jun 2006 Location: Cochin Posts: 12 Thanked: 7 Times	Which is better ?AC ON or Windows rolled down in high speeds Hi all, I have somewhere read that on high speeds, if you roll the side windows down, it will affect mileage as the resistance caused by the air increases. How does this drop in mileage comparable to putting ON the AC at high speeds ?
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16th June 2006, 10:05	#2
burjiis BHPian Join Date: Nov 2005 Location: Mumbai Posts: 51 Thanked: 36 Times	Hi Prince, I distinctly remember one of the Auto Magazines (I think Autocar) mentioning that the VTEC gave better fuel efficiency with the AC on at high speeds than with the AC off and the windows rolled down. So, if you own an OHC you got your answer. Would be interesting to know about other cars too. Regards, Burjis
	() Thanks

16th June 2006, 10:17	#3
ajmat Team-BHP Support Join Date: Feb 2004 Location: Bangalore Posts: 14,866 Thanked: 27,981 Times View My Garage	High speed, windows down - like driving with a parachute
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16th June 2006, 10:28	#6
1100D Senior - BHPian Join Date: Jun 2006 Location: Calcutta Posts: 4,390 Thanked: 4,096 Times View My Garage	How about Windows rolled up and AC off. Isn't that the best regarding FE?!
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16th June 2006, 10:36	#8
kb100 Senior - BHPian Join Date: Feb 2006 Location: Bangy Boy! Posts: 1,555 Thanked: 21 Times	nobrainer.. windows rolled up and AC running will give you more milage... and comfort!... wind noise/roar is a major factor in travel fatigue..
	() Thanks

16th June 2006, 11:51	#10
k36 BHPian Join Date: Dec 2005 Location: Pune Posts: 133 Thanked: 21 Times	What a pity! ... on highways where there is little pollution... where you can enjoy the fresh air you need to keep the windows rolled up for the sake of mileage. On the other hand in polluted environment of cities.. in the crawling traffic you need to keep windows rolled up ... and AC ON .. at the cost of mileage!
	() Thanks

16th June 2006, 14:37	#11
revharder BHPian Join Date: Jan 2006 Location: New Delhi Posts: 460 Thanked: 56 Times	AC ON and windows up and then driving at 'constant' high speed will give you really good fuel economy. just try to visualise the scene ahead and try to maintain your speed accordingly. our very old santro still gives us 17+ kmpl while cruising at abt 100-110kms on NH1 with AC ON for 100%. although being a breadbox design, windnoise do irritates a lot, but we have a thing called music system to take care of that noise! Last edited by revharder : 16th June 2006 at 14:39.
	() Thanks

17th June 2006, 00:51	#14
Kaizer Sozay BHPian Join Date: Apr 2005 Location: Melbourne Posts: 333 Thanked: 5 Times View My Garage	I am for AC on on along drive. My Zen gave me an Avg of 19.5 on a drive Bombay to Goa with the AC on all the Way...
	() Thanks

17th June 2006, 15:14	#15
micraft BHPian Join Date: Apr 2006 Location: Bangalore Posts: 108 Thanked: 289 Times	[FONT=Arial]If a car moves at 80km/hr with windows rolled down, how much would it move at with the windows [/FONT][FONT=Arial]rolled up?[/FONT] [FONT=Arial][/FONT] [FONT=Arial]?[/FONT] [FONT=Arial] [/FONT]
	() Thanks