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Mythbusters Research

342Four

By 342Four,
in General Automotive Discussion

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342Four Grand Master

342Four

Posted
Posted

OFFICIAL RESEARCH BY MYTHBUSTERS:

Mythbuster proved last night (last night in WA - on TV) that it is more economical to drive whith your windows down than with ur windows up and aircon on flat out

two suv's with the same payload with 5 gallons of petrol where sent around a track to find out which would stop first.

suprisingly, the car with the aircon on was the one to stop the first

the other suv went for a further 15 miles

the reason that this is suprising is that one would have thought that the drag created by all the air being sucked into the car with the windows open would have made it slow down first, BUT, mythbusters have shown that it is more economical to drive with the windows down

So there u go fellas - windows down then in the future seems the way 2 go!!!

:):rofl::) :cooldance

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342Four Grand Master

342Four

Posted
  • Author
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yea that true that aircon sucks power,

but one would imagine that the drag factor created by all the air pouring into the car with the windows open would make it less efficient than with the aircon on

and of course this would change from car to car

a small car with the aircon on full blast will drain alot of power and fuel, but on a big car, like the suv's that they where useiong (ford explorer xlt's i think - if i remember rightly) you would think that it would be more efficient for the aircon to be on, than the wiondows open

but hey, it is interesting

PS:

is anybody willing to do some test with there skylines - it would be interseting to see what the diff is (by tests i mean like 5 litres of petrol and see how far u go sort of thing at a constant speed)

342Four Grand Master

342Four

Posted
  • Author
Posted
i always drive around with my windows down.  

how else can chicks listen to your fully sik bass while you cruise around with your arm out the window?

too true mate, too true

:bahaha: :cooldance :bahaha: :cooldance :bahaha:

Zahos Mentor

Zahos

Posted
Posted
they always said aircon sucked the power.. haven't u ever put on aircon whilst climbing a big hill in a small car?

But this test was based on cruising on the highway. Stop start driving and hill climbing are not part of the conditions where this myth was thought to be true.

But I think the caterpault was f*cken funny sh*t!!!

Especially the way it fell apart afterwards....

writeoff Mentor

writeoff

Posted
Posted

What surprised me about this episode was that it was a myth. I watched this with a mate and we both assumed it was common knowledge that running a car with the a/c on would use more fuel than just having the windows down.

That trebuchet was funny as... poor buster!

(B1) MR_fanny Grand Master

(B1) MR_fanny

Posted
Posted

they should have filled the bucket of that crane with watermelons or a dead cow get the most out of it:D:D

werent that bright were they when they first decided to fill the cars up full and drive for 7 hrs...lol...then having to pump it out by hand...haha.

ACA did a test yesterday too on how much k's u can get out of regular, premium, and super premium. they were smart enough to just fill the cars up with 5ltrs to run em dry. the only smart thing ive seen from that show.

scathing Grand Master

scathing

Posted
Posted

Its not that surprising, really. It also doesn't help that SUVs have the aerodynamics of a brick shithouse, so making the aerodynamics slightly worse has less relative effect than making the engine power a compressor that's not increasing the air density going in to the engine.

Try the comparison on a car with a low drag coefficient, and it would probably be a lot closer.

yaf28f Rising Star

yaf28f

Posted
Posted

Hey B1, I missed ACA, can you give me a quick run down?

I personally think that the "lift drop" did more damage to Buster than the "crane catapult".

they should have filled the bucket of that crane with watermelons or a dead cow get the most out of it:D:D

werent that bright were they when they first decided to fill the cars up full and drive for 7 hrs...lol...then having to pump it out by hand...haha.  

ACA did a test yesterday too on how much k's u can get out of regular, premium, and super premium.  they were smart enough to just fill the cars up with 5ltrs to run em dry.  the only smart thing ive seen from that show.

predator Grand Master

predator

Posted
Posted
But this test was based on cruising on the highway. Stop start driving and hill climbing are not part of the conditions where this myth was thought to be true.

but if its sucking power, its still sucking power, it just becomes more obvious when you are climbing a hill and the car has very little power.

like writeoff was saying, most people would say that if you asked them regarding the aircon that it draws more fuel.

I am pretty sure *any* car with aircon on, you'll notice worse fuel economy, as the compressor is creating drag on the rest of the belt system, and hence the whole engine turning over, requiring slightly more power to get the same result.

xRHETTx Mentor

xRHETTx

Posted
Posted

Hey guys i think we are forgetting that the research they did was a bit flawed. I thought it was a widely known fact that it is more economical to wind ur windows down compared to use the aircon, but only up to about 80km/h. This is the point when the extra drag created by the windows being open becomes greater than the power the aircon uses.

In the first test on mythbusters, run at 55mph = 89 km/h, they found that it was more economical to run the car with the aircon on.

In the second test, they ran the cars at 45mph = 72 km/h, because it wasnt safe to go around the track for that long with their shit SUVs. In that test they found it was better to go with the windows down.

It was the difference in speed that made the difference, youre still better off with the windows down at speeds up to 80km/h, then using the aircon at speeds above that.

Rhett

merlin6014 Enthusiast

merlin6014

Posted
Posted

i didnt get the point of it - i thought it was common knowledge that the a/c sucks power (therefore uses more fuel), you can tell as soon as you turn it on.

I used to own a BA Falcon XR6 with the instentaneous fuel readout display, if you held it steady on the the freeway at 110km/h it would read about 10L/100km, winding down the windows made no difference, turning the air-con on, it would instantly jump to 12L/100kms.

(B1) MR_fanny Grand Master

(B1) MR_fanny

Posted
Posted
Hey B1, I missed ACA, can you give me a quick run down?

I personally think that the "lift drop" did more damage to Buster than the "crane catapult".

sure, unleaded konked out first then super unleaded(98ron) a good couple k's more and suprisingly premium(95) did a couple more k's then died in the ass. was a good test as it wasnt on a straight but normal roads with ups and downs and sharp turns and everything to simulate normal driving.

yaf28f Rising Star

yaf28f

Posted
Posted

Cool, thanks for that. not that it will stop me from using premium(98)

sure, unleaded konked out first then super unleaded(98ron) a good couple k's more and suprisingly premium(95) did a couple more k's then died in the ass.  was a good test as it wasnt on a straight but normal roads with ups and downs and sharp turns and everything to simulate normal driving.
boston Apprentice

boston

Posted
Posted

i think that they should have put a bit more thought into it..

consider this.. i know 2 people who have the same type of car.. one of them would stop after using 52L in the tank, the other after only 47L.

Reason: the fuel pickup was mounted slightly differant.. from the factory..

the fact that they pumped out the tank completely tells me that the test was not well done.. it would have been better to drain the tanks completely, add a little fuel and drive the cars around till they stop.. this would be the true empty point of the car.. there may still be some fuel in the tank but the pickup wont get it..

then with both cars at this point conduct the rest of the test as they did..

my $0.02

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