Air Con & Fuel Consumption

[Stringent]

I know having the air conditioning on takes up fuel, but is it really that much? Heard conflicting reports in places. Some people say it drinks, others are more conservative. Just wondered what you car gurus thought.

[Skii]

On average you'll lose about 5-7 mpg with the aircon on.

I reckon I'm about 7-8, but it does make a considerable difference.

[doctor_prox]

May sound stupid but i dont see how it uses fuel, i mean the engine is running regardless and i dont see how it would be that much resistance so im kinda lost there.

[Jiff Lemon]

Air con works by driving a compressor. The compressor creats drag, so the engine has to work work harder. When an engine works harder, it uses more fuel.

The other factor to consider is the size(in CC's) of your engine. Smaller engines will be affected more by aircon than larger one.

On the whole, running Aircon is actually more economical than driving down the motorway with a window open.

[J4MES]

the compressor draws power from the alternator, which means the engine's working harder...

edit: or it runs of a belt, running of the crank...

[Richie]

The other factor to consider is the size(in CC's) of your engine. Smaller engines will be affected more by aircon than larger one.

True. I really dont see any diff between AC on and AC off in my car.

[McMav]

You live in scotland how often you need aircon on

[Jiff Lemon]

You live in scotland how often you need aircon on

Actually, its a misconception that aircon is just for cooling, it also removes the moisture from the air. Steamed up windows first thing in the morning? Whack the aircon on and watch that mist disappear.

Once you've had a decent aircon system, you'll miss it sorely in a car without.

[XTR]

Actually, its a misconception that aircon is just for cooling, it also removes the moisture from the air. Steamed up windows first thing in the morning? Whack the aircon on and watch that mist disappear.

Once you've had a decent aircon system, you'll miss it sorely in a car without.

yeh i use it on a morning to clear the windscreen
Works in seconds.... its great stuff


i dont notice any difference in MPG though with it on or off.... but then again my MPG is so low in the first place... that i dont care no longer.........

[McMav]

Actually, its a misconception that aircon is just for cooling, it also removes the moisture from the air. Steamed up windows first thing in the morning? Whack the aircon on and watch that mist disappear.

Once you've had a decent aircon system, you'll miss it sorely in a car without.

I know I live in Scotland 2 was a joke.

[Stringent]

So you might loose a few MPG, but how much then is that in cost, not a lot ... really. The next car I get HAS to have air con, this England just gets mental in the summer.

[Richie]

Only problem with clearing windows with it is, if you turn it off too soon, they mist up just as quick


Most ppl think AC is just to give out cold air but it does sooo much more. It draws in the stale air, dehumidifies, filters, cools and then adds a small amount of moisture back in (tiny compared to what it dries out).


The resultant air that comes out the vents (if system is clean) feels unbeleivably pure and clean when it hits you