I have been using my car for a while now. since I have been a kid I have always heard that air conditioners increase the fuel consumption of cars. I don't use the air condition in my car mainly for this reason but lately I decided to start using it (because of the weather). I don't really see any noticeable effect on my fuel consumption. Does this really affect the fuel consumption or its just a myth? I wish to know. or is it for some specific brands of cars?

air your views on this. I really wish to know. thanks

yes it does. Use of air conditioner adds more load (compressor) to the engine which results in higher fuel consumption. The rate of d consuption varies with the capacity of the compressor and engine size. The fan speed (blower) also affects it as it determine how frequent the thermostat trips which directly translate to working time of the compressor

thanks for that detailed explanation. but I don't notice any change in my car's fuel consumption, it has too be that my engine is strong or something?

It's also depends.. It has been noted that on highways it's might be better to windup and turn on the AC in other to avoid air drags coming from the Window which can also affect your mpg in some cases even more than if u had your AC on and windows up. For the sake of aerodynamics it's sometimes better to wind up and turn on the AC.. But in normal city driving might be better to just wind down.. Also as noted the size of your engine also plays a big role.

On high speed it does not! On low speed it does! Shikenna.

I will look keenly into dis on low speed too. seriously although there may be some elements of truth in it. the way people exagerrated then effects when we were small did not even make me touch the AC the first six months that I got the car. but since I considered using it I have really been enjoying it at almost no extra cost.

one other thing I will like to confirm is this.

does the use of AC all the time have effects on the efficiency of the engine and its lifespan. also does it have any negative effect on my health?

The use of A/c add more load to the engine and will make the engine wear faster.
You may be enjoying the car because its still new/tokunbo but as time goes on, you will see the reality
V6/V8 engines are big enough and can accommodate A/c very well without much difference in fuel consumption but 4cylinder engines are not like that, you will definitely feel it on them that yu're using A/C

From my own experience there is no difference in the fuel consumption. I have driven a 1999 V6 Camry for nearly 5 years now, and for a week while the the AC was broken I did not see any difference in the fuel consumption.

Even if there was an increase in fuel consumption that should not be a big deal. I believe that as human beings, we should value ourselves above the money we think we are saving by switching off the AC. Life is for the living.

From about 80km/hr n above, no difference. When d car becomes light @ high speed, fuel consumption is reduced.

All things being equal for the car......there shouldn't be any diff in fuel consumption when u use AC nd when u don't.....Ac is an electrical device just like in ur home ...so it consumes power on ur battery.....but when all conditions aint equal like...the engine aint as new as b4 nd power has reduced....despite the AC is an electrical device its still connected to the entire engine frame..so once the AC is on it puts extra pressure on the engine dats not so new anymore ...nd extra presure means extra fuel consumption....dats my own view

coolsegun2002: All things being equal for the car......there shouldn't be any diff in fuel consumption when u use AC nd when u don't.....Ac is an electrical device just like in ur home ...so it consumes power on ur battery.....but when all conditions aint equal like...the engine aint as new as b4 nd power has reduced....despite the AC is an electrical device its still connected to the entire engine frame..so once the AC is on it puts extra pressure on the engine dats not so new anymore ...nd extra presure means extra fuel consumption....dats my own view

absolutely I share ur view.


how I wish I get a mechanical engineer to clarify dis,. I feel feel consumption should not be affect by d use of ac provided d engine is good. cos for me whether am in d hold up, driving slow or fast I don't see any difference in the fuel consumption.

I just wanted to be sure. I don't like saying things am not sure of just because of a single experience I have.

Yes it affects fuel consumption, however letting your windows down may affect it more (depending on your speed)
Check out
http://auto.howstuffworks.com/fuel-efficiency/hybrid-technology/driving-with-windows-down2.htm
very insightful
If you're searching for a good rule-of-thumb number for when it's best to open the windows and switch off the air conditioner, according to some experts, the cut-off should be around 40 miles per hour (64.4 kilometers per hour) What's the reason? Well, at low speeds your engine is producing less power, so it would have to work much harder to power accessories like the air compressor. When the engine is operating at faster speeds, it's already producing ample power for both the engine and additional equipment

When a car is made the a/c is taken into consideration when then fuel efficiency is measured and except the a/c is locally assembled the compressor is measured in tandem with the engine size so that it doesnt consumed too much of d generated engine power .the compressor is directly connectd to the engine so definitely it runs on fuel it is the cooling fan inside the car that uses electricity from the battery/alternator bt that too is connected to the engine so invariably it still uses fuel bt anyways the difference is not so much like most people fear its just a common phobia its the older rear wheel drive vehicle that any more load on the engine would have been very noticable bt with this newer front wheelers its not too bad cept your car is faulty.now let me shock you do you know that ur radio, headlights ,wiper also affect ur fuel economy even ur tyre pressure and the number of people u carry bt thats story for another day

andywaves: .now let me shock you do you know that ur radio, headlights ,wiper also affect ur fuel economy even ur tyre pressure and the number of people u carry bt thats story for another day

Whoa! this is getting more interesting. I really will like to know how this is possible, but from the point you made can I say, the ac does not "use" more of your fuel more than your radio or headlight does? will that be correct.

seriously I have learnt more. a so called engineer I asked said it consumes more fuel when you just switch it on and stops consuming after few minutes.

No sir I did not say that. Each electrical device has a power rating some 5watts some up to 70/100w or more depending on size n function and each of this device draw their power not from d battery directly like most people think bt from the alternator or generator as called in some quarters the primary work of the battery is to start the car if u draw current directly from d battery it wont last the end of the day


The alternator works exactly like ur generator in the house it is made up of an electrical coil that generates power as it spins the current that is generated is what is used to power d vehicle n keep d battery charged

There is an optimal amount of power generated by each alterntor depending on its rating so each load draws its own quota from d alt so more load more power, more power more fuel at lower speeds at higher speed the alt is at is optimum somewhere abt 76km or more