Toyspeed.org.nz Message Board

Its HOT! What do you think uses more fuel? Driving with the windows open, or using the AirCon constantly?
This is for a long distance journey, mainly 100kph.

I think A/C uses more fuel but is your long term comfort worth a few bucks?

Window down until you hit 80kph (i.e. when it starts messing the missus hair). Then switch to air-con.

If it's real hot then both.

Personally I very rarely use air con. I don't like the way you can feel it cut in and out while you're driving.

BZG Wagon wrote:If it's real hot then both.

Not sure if serious.... always thought air con only works if windows are shut? Though the extra fuel usage by using both would be pretty mean, bugger the greenies.


Not sure which would use more fuel, i'd say the drag on the car from open windows wouldn't be far off aircon usage. I'd go air con everytime though, if you want to hear anything @ 100km/h anyway. Sadly my aircon keeps breaking down so I go windows down

A/C all the way. Keeps the car nice and cool and you don't feel like you're in a hurricane. Uses bugger all gas too unless you've got a really inefficient car.

Try Sydney without AC.
Gonna die in shirt and tie outside

The problem I have is that the AC works real well, but I only have a 1500 Sprinter/Corolla thing. You can really feel the loss of power when the AC is running, feels like the handbrake is on.

Well I've got an EP90 starlet LIFE in sydney, and work is 1.2 hours away.
/stop complaining.

thegreatestben wrote:Well I've got an EP90 starlet LIFE in sydney, and work is 1.2 hours away.
/stop complaining.

Lower Hutt to Sydney in 1.2hours. In a starlet! THAT, is AMAZING!!!!!!

So who's going to start writing a letter to myth-busters?

Id go for windows down most of the time, aircon when its needed tho ( like whens its hot and raining)

less than 70, windows open. Much over that the air con is more efficient. Its a bit of a generalisation, though, I guess it may vary from one car to another.

Mythbusters- A/C vs. Windows MiniMyth
http://www.youtube.com/watch?v=ZRt20C6NL-c

Aparanlty by 15% windows down is more efficient. Still like a bitta A/C on a really hot day!

i love my aircon i will never ever part with it

i get people going "nah $&#$% it off you are losing power parasitic loss rah rah rah"

i just tell them to shut the $&#$% up - im the one that's cool and collected and they are the ones with a t shirt made out of sweat

ive never found nz to be hot enough for ac, always preferred havign the window down anyway, get decent fresh air that way


BUT

over here in aus i would die without my ac



didnt mythbusters do a thing to see wether ac or windows uses more?

MAC_HATER wrote:i love my aircon i will never ever part with it

i get people going "nah $&#$% it off you are losing power parasitic loss rah rah rah"

i just tell them to shut the $&#$% up - im the one that's cool and collected and they are the ones with a t shirt made out of sweat

yea but you drive a 1jz you wont notice the power loss and fuel economy obviously isnt your biggest concern.

shihad wrote:yea but you drive a 1jz you wont notice the power loss and fuel economy obviously isnt your biggest concern.

exactly - but actually you do notice the power loss and you certainly feel when it activates and shuts off mostly while town driving though

also the fact that AC'd air demists windows so much faster when needed

The earth wire to the magnetic clutch on my ac is broken so I took the belt off the engine and the tensioner pulley so the engine doesn't have to spin things it won't use. The pulley is very heavy too so that reduces car weight. I would like ac on some days but windows down works fine for the rest.

The mythbusters segment on it isnt really right.

The efficiency difference depends completely on how aerodynamic your car is to start with.

If your car is like a big giant brick, then the percentage of difference that winding the windows down creates is small, where as it makes a higher percentage of difference on an aerodynamic car.

It's also not a fair comparison in that, what is the goal temperature?

You cant wind your window down far enough to reduce the inside temperature to below ambient, where as this is simple with aircon.

Just having the fan on without AC is probably a more direct comparison to having the window cracked down slightly.

Seeing how this draws air from a high pressure area on the car already, with minimal disruption to aerodynamics (hence why they put the inlet there) it would obviously be more efficient than winding a window down.

A rediculously easy way to tell, is to have a multimeter monitoring your injector pulse width.

If it's higher doing one thing or the other at the same speed, then there's your answer.

I'm in an NZ new Corolla wagon circa 1992.

The one feature the car has, is central locking.

You want the temps down, wind the windows down and crank that fan up!

Damn near died on Christmas day stuck in SH1 standstill traffic and many degrees of warmth. Would have sold the car for $10 and a bag of ice that day.

I usually wind the windwo down.
On a long trip where is is really hot I'll use a/c but I hate feeling it kick in and out, I keep thinking there's something wrong!
you really notice it in a 1600 Corolla!