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Which is the most economical ?

Penners

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#1
Which is the most economical ?

Driving with ones window down or driving with the window up and the aircon on ?
 

iant

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#5
Depends on your speed apparently.

On the motorway at 70mph it's window up.

In town at 30mph its window down.

Can't remember the tipping speed!!
 

Spectre

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#6
I think the air-con one was one that wasn't conclusive, I think.

Something to do with having windows down AC off at slower speeds and vice-versa being the most efficient.
 

jaffa

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#7
Mythbusters used a computer to predict it and it said aircon ON was more economical but when they tested it round a track, the windows down/aircon OFF went 30 or so more laps so they concluded that windows down was more economical.
 

krazylegz

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#8
well i use my air con all the time, i have windows and sunroof open when its warm and on normal slow roads, but on hot days and when on roads over 30mph its air con as i just couldnt stand the noise of the wind.

i dont really see a difference using air con and not not my average fuel is still about 47mpg when using it or not and still get roughly 650-700 miles on a tank

but i would personally say that windows up and air con would be more effective as it would cause far less drag, plus new cars air con now are far more effiecent than in the olden days, after all the compressor is only belt driven, being driven by the fan belt which is already spinning;)
 

liambalfour

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#9
Windows down vs. air conditioning
"Urban puzzle": it is more efficient, on a hot day, to run with the A/C on and windows up than to run with windows down (b/c of increasing car's drag).

Computer-based mpg measurements: * 11.7/11.8 with A/C on and windows up * 11.7/11.8 with A/C off and windows up * 11.3 with A/C off and windows down

So, according to the computer, it's better to use A/C with windows up.

This was too quick and easy for TV, so they decided to stage a seven hour marathon, race-til-you're-empty duel, with Jamie driving an SUV with A/C on and Adam driving an SUV with windows down. Though, once the safety inspector intervened, it was no longer a seven-hour marathon, it was a bit slower (45mph instead of 55mph), and a lot shorter (only 5 gallons each).

Jamie's A/C car ran out of gas first -- Adam's windows down SUV ran for another 30 laps -- completely contradicting the computer mpg estimate. Computer estimate based on air flow into the engine, so it would appear that it is unable to properly model the difference between A/C and windows down.

Mythbusted

source http://kwc.org/mythbusters/2004/11/mythbusters_boom_lift_catapult.html