Scirocco Central

Hiya, just wondered if anyone technically minded knows if having the air con on uses some of the hp from the engine? I know it increases the fuel used so I am assuming it does...

Or if you floor the accelerator does it temporarily switch it off?

Cheers, Matt

Not sure about the temporarily disabling aircon.. but my Roc definitely is slower pulling away if the aircon is turned on, the power for it has to come from somewhere

Have to say, I don't notice any difference whether it is on or not - I'm sure they have become a lot more efficient over the years

*170 tdi torque is fairly hefty mind!

I've heard that it's true, but it'll only sap a few hp. I'm not speaking for the scirocco but generally I think the AC pulley is being turned all the time but when the AC is on the clutch in the pulley engages and increases torque needed to turn it as it spins the compressor too.

Mythbusters say its more energy efficient to have your windows down and aircon off below 50mph anyway

Ben90 wrote:Mythbusters say its more energy efficient to have your windows down and aircon off below 50mph anyway

Not that that's much use to you in the depths of winter, though!

RoccoTom wrote:

Ben90 wrote:Mythbusters say its more energy efficient to have your windows down and aircon off below 50mph anyway

Not that that's much use to you in the depths of winter, though!

Or in fact in the middle of summer.when you want the cabin temperature to be lower than ambient.

Indeed, in winter I'll have the windows up and the heater on thanks!

For summer time, Ambient + wind = lower temp than ambient Perfectly adequate for those scorching British summer days in my opinion. I have aircon but i'll only use it maybe a few times a year in the middle of summer mainly to cool down a roasting cabin. Some people who go for big powaa bin the whole aircon system and fit a non-AC belt!

Ben90 wrote: I have aircon but i'll only use it maybe a few times a year in the middle of summer mainly to cool down a roasting cabin.

You should use your air con more than a few times a year to keep it in good working order.

http://www.autokool.co.uk/faq_13.html" onclick="window.open(this.href);return false;

Air con also removes moisture from the air so de-mists the windows quickly, not just a tool to cool you down in the summer. I'm sure I read somewhere it saps about 10bhp, which is very noticeable in my other halts 1.0 Peugeot 107

Thanks for the feedback.

I normally have the air con on because it stops the screen misting up in the winter and is nice in the summer.

I don't notice the power drain to be honest but I think I'll stick with my minor ocd of turning it off if I'm overtaking someone crawling along on an A road... just in case I need the extra couple of HP!

I've just always got it on - air feels so much nicer when it's not full of moisture.

same here! always leave mine on......there's just something about nice refreshing dry air!

Aircon increases fuel consumption by between 6 and 10% - the lower level being for the larger engined cars. I therefore assume that the fuel/energy used by the aircon reduces power available at the wheels by the same amount. Leaving windows open above about 50mph causes extra drag which has the same effect.

I rarely, if ever use aircon.

In the 20 odd thousand miles I've done, it can't be more than 3 figures I've driven with aircon on at all.

With my old Civic Type S, the manual said it used 0.01% extra fuel having the air con on. It didn't zap any power and I certainly didn't notice it was using more fuel. The Rocco seems a bit different - if you go by the trip computer having the air con on reduces the instant consumption by around 10mpg. I haven't noticed any loss in power though. I leave mine on all year, for some reason most people assume air con is only for hot weather but as someone else said it demists your car in winter.

Auto Express did a pretty thorough test some time ago and found that Aircon barely affects MPG at all when driven at higher speeds due to the fact the vast majority of the engine's power is being used to move the car along, at low speeds/urban driving the aircon uses a bigger slice of the power the engine is producing.

Air con is brilliant in the summer if you have hay fever. Your eyes can be streaming, 5mins in the car and you are back to normal.

Ryy wrote:I rarely, if ever use aircon.

In the 20 odd thousand miles I've done, it can't be more than 3 figures I've driven with aircon on at all.

It's widely reported that if you don't use the A/C the seals can dry up and your coolant will seep out

10minutes / week is the recommend usage. As said earlier in this thread, it's ideal for clearing misted windows and maintaining the right temperature in the summer months

Just to be clear.it's not engine coolant that would seep out it would be refrigerant gas. Although it does provide a cooling function it's not normally referred to as coolant to avoid confusion with engine coolant.

Yeah that's the coolant I meant - refrigerant