Petrol use and aircon.

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intrade, Dec 31, 12:04am
yes thats is again managing the aircon process- you are correct

msigg, Dec 31, 12:11am
As above it will use more gas with the A/C on, going up big hills with your foot down will use the most gas as the mass you are moving is alot harder, I would expect you will get another 50-80 km if you drove it in a nice way, taking it easy. As for cost petrol is dirt cheap now so who cares.

aredwood, Dec 31, 12:15am
What I don't get is people driving in expensive cars with the windows down in slow moving traffic. If you can't afford the small amount of extra fuel usage from using the aircon, You shouldn't have bought a $20,000+ car.

intrade, Dec 31, 12:18am
they might even have the aircon on and woder why its not doing its job,
because they dont know the basic principle of airconditioning.
even the word holds the clue
air- conditioning - condition the air in the box you are inn.

msigg, Dec 31, 12:25am
No matter what car I drive I love the window down, it gives you that sense of freedom and to smell the roses, None of the glass box driving for me, each to their own.

bill-robinson, Dec 31, 12:41am
or the cowyard as you drive past, or the sheep truck you are waiting to get past. wonderful smells of the countryside

msigg, Dec 31, 12:46am
Yes you are right bill-robinson, even to smell the cow yard is great after being in Auckland city for a year, then you know your on holiday and away from the big smoke, doing what you want, when you want and how you want.

datoofairy, Dec 31, 1:32am
Thanks everyone for your replies.
Msigg, so I can safely allow around 450k's per tank of gas, assuming I dont thrash it on the hills (which I wouldnt usually do) and assuming its an average day where I dont need aircon or the windows down.
Thats all I need to know, just some ballpark figures to plan with.
Thanks :o)

neell, Dec 31, 1:57am
Buy yourself a motor bike, much better.

bill-robinson, Dec 31, 2:35am
the very reason i do not and will not live in a city but I use the A/C in the car as i do not like the wind noise and buffeting of an open window

elect70, Dec 31, 2:51am
Regardless of a/c efficiency it still takes around 2 kw to drive the the compressor , it may not be so noticeable on a mid size engine , but on a 1.3 l you sure notice it going up hills . I hired a nissan note other week & going up a moderate hill it changed down to 2 in the auto box & if switched it off it would pick up revs & change into top . There fore it will have a direct effect on fuel consunption .

socram, Dec 31, 3:08am
In slow moving traffic, I prefer the window down. A/C off. Small cars, as above, rarely use the A/C anyway.

It is a habit I have always had, winter or summer, particularly coming to a road junction. Probably a legacy of learning to drive when hand signals were compulsory to pass a driving test, even though the cars had the new fangled flashing indicators!

Check mirror; open window; check mirror again; signal; brake; check mirror again; turn - in that order.

pebbles61, Dec 31, 4:44am
Wait, wat lol

gammelvind, Dec 31, 7:43am
My A/C is always on summer or winter. I am one of those who likes a cool interior in summer and a dry one in winter. Driving with the window open, for me, is not a pleasant option in the current weather. I get about 500km to a tank, 2l Toyota, tried once and drove a tank load with no A/C, for me it was unpleasant and tiring though I did get another 25(ish) km to the tank, I will very happily pay that extra fuel cost to have a pleasant relaxing drive.

intrade, Dec 31, 7:51am
correct in content discription. we dont want to go anal over if its now 1.159998kw or 2kw
what ever "the load" is will add to fuel used to make the ac compressor do its job and the blower motor draws power and all the rest of the tini addons plastered to make it more efficient in doing so.
"AC is a load on the engine" .

gamefisher, Dec 31, 7:58am
Presuming it has a 50liter tank that would mean an extra 2.5 liters yes I would pay that on 500 k trip to have pleasant air.

marte, Dec 31, 10:33am
In trade, your spelling is terrible.

I have often wondered if connecting the aircon clutch switch up to the brake light would work.
It would mean that the aircon would only work when you are braking and that would put load on your engine, increasing your engine braking.
You would not even actually have to use the brakes, just enough to trigger the brake light switch and straight away you would start slowing down.

Since the aircon takes a bit of time to get up to pressure, and then runs on for a while once its off, and still cools during that time. On average its cooling down most of the time.

I still cannot figure out why people take off the aircon belt to "save petrol as the aircon uses up power".
Saw last week where they took out the main hoses, "to save fuel" duh!
But they left everything else as it was.
If you don't want the aircon to use power, don't turn it on!

dublo, Dec 31, 9:03pm
With our 1999 V6 Accord there is no long-term discernible difference in fuel consumption, summer with air con on, winter occasionally on to demist windscreen, town or open road work. We keep careful records of fuel consumption.
It was a different story with a 1985 Rover V8: turn on the aircon and, on the open road, the car would slow down about 3 km/h at the same throttle opening, use more throttle to maintain speed and it would drop from 24 to about 22.5 miles per gallon!

intrade, Dec 31, 9:11pm
#26 you are correct i can see one flaw in your thinking of hooking up the clutch to the brake switch.
How is the computer to controll the clutch of the compressor if you hook it to the brake switch?
because if you dont stop the compressor it will ice up its why it cycles on and off the clutch.
Modern cars will already do what you are talking. they even turn off the alternator and some switch off cilinders to save fuel , whom they then use to treat emissions in the exhaust.
alternator ford smart charger is one of them ecu turned off alternators for example.
most cars will turn off the aircon clutch instantly when you press the gas pedal to the floor . i could try to see if my 95 toyota does that . hmm as the aircon still works .

elect70, Aug 9, 5:56pm
Takes about minute for it to actually produce cool air , has to absorb heat in the evaporator first before the cabin . so no it wont work . I use mine if the car has been parked in the sun all day & it takes hour of driving before the cabin is down to 20 C . rest of the time i still drive with window down & elbow out , as thats all we had in 19 65