AirCon and Ur Fuel Consumption

[Casey]

Does adjusting the temperature of aircon affects FC? Meaning higher temp = compressor kicks in less often (as its always in a on/off cycle) = lesser engine load = lower FC.

Edited September 22, 2006 by Casey

[Mzrmazda3]

Seems like it is so according to some posts which i have read from the forums

Edited September 22, 2006 by Mzrmazda3

[Quantum]

I am not aware much FC difference when aircon on or off[dizzy]

[Sunray]

I think higher a/c temp means giving lesser load to the comp.

 

Thus the comp will draw lesser load from the engine.

 

Therefore, FC should be lower.

[Casey]

is it true...as in technically??? does the compresor goes on and off?? and is really the effect on the engine load so considerable tat it affects the FC of the car???

 

this is wat i want to find out, not theory-wise.

Edited September 22, 2006 by Casey

[Optionr]

You try driving 1 week without turning on your air-con and see if your FC improves anot. For my Jazz, FC definitely much better when I switch off my air con!!!

[Gilgamesh]

Its is confirmed for my car by own testing. Keeping my driving pattern, route taken and the brand and grade of petrol pumped the same, if I drive wif 80% or more of the time with A/C on, the FC is ~9.5 to 10.5km/L. If I drive wif around 20~30% of the time wif A/C on, the FC is 11.5 to 12.7 km/L. The best I achieved wif A/C off 90% of the time is ard 13.5km/L.

[Tkseah]

Erm.. I believe Casey is asking whether got diff when setting A/C to very cold and setting it to not so cold. Not between having A/C on or off.

[Burgerdog]

This is taken from one.motoring:

 

Close window while driving

 

Don't drive at higher speeds with windows wide open. It increases the aerodynamic drag on the highway and lowers fuel economy.

 

 

Minimize the Use of Car Air-con

 

Operating an air-conditioner in hot weather can increase fuel consumption by more than 20% in city driving. Therefore park in the shade to keep car cool and reduce the need for air-conditioner or use the vent setting as much as possible to minimize the use of air conditioning.

 

The thing is, if you off your air con, then you'll have to open the windows.

If your windows are open, it causes drag, which increases FC.

 

So how?

 

And with the weather here, how high can you set the aircon temp?

If it comes to a point where there's not much effect, then might as well not on it.

Edited September 22, 2006 by Burgerdog

[Mzrmazda3]

 

That's why not much people can tahan without winding down the windows and not using aircon for say 45 mins on a morning say 8.00am during a normal weather day

 

I have tried this before (No aircon & No winding down of windows for 45 mins) and yes FC improved by 1-2km/l but you'll reach office in sweat

Edited September 22, 2006 by Mzrmazda3

[Burgerdog]

Wah!!!

You also can leh!!!

45 mins without aircon and wound-down windows...

 

 

Was wondering if the windows visors can aid in cutting down the drag if you wind down just before exceeding the visors.

 

Anyone here with visors can share?

[Gabriel]

i onli noe 1 thing...

no a/c ....better pick up...

good for cheonging traffic light to traffic light

[Gilgamesh]

actually wanted to ask him to check out his a/c temp ctrl mechanism b4 answering this but dropped the idea coz not specialist in car a/c - only studied building a/c in University but not car a/c and dunno if both works the same way (most prob lah but I think the mech bros in this forum is more qualified to answer this)

 

Anyway, if it is controlled by thermostat, it will definitely help since the compressor will shut off when the required temp is reached and hence reducing the load on the engine. My car a/c compressor is those "always on" type and it mixes cold air from the compressor and hot air heated by the hot water from the radiator to regulate temp so the only way for me to test the affect of FC by the a/c is to switch it off.

[Gilgamesh]

i onli noe 1 thing...

no a/c ....better pick up...

good for cheonging traffic light to traffic light

 

Yup!!! The a/c on off button is the Turbo button for my car. Really comes in handy when someone jio u for a traffic light drag race... Ever beaten a few 1.6L Beng's cars wif my puny 1.4L engine with Turbo switched on.

[Gilgamesh]

This is taken from one.motoring:

 

Close window while driving

 

Don't drive at higher speeds with windows wide open. It increases the aerodynamic drag on the highway and lowers fuel economy.

 

 

Minimize the Use of Car Air-con

 

Operating an air-conditioner in hot weather can increase fuel consumption by more than 20% in city driving. Therefore park in the shade to keep car cool and reduce the need for air-conditioner or use the vent setting as much as possible to minimize the use of air conditioning.

 

The thing is, if you off your air con, then you'll have to open the windows.

If your windows are open, it causes drag, which increases FC.

 

So how?

 

And with the weather here, how high can you set the aircon temp?

If it comes to a point where there's not much effect, then might as well not on it.

 

Don't worry bro, the drag effect will only be significant when u r driving at 90km/h and above. U can reduce it by opening only 1 window so as to create a positive pressure in your cabin relative to the external gushing air. By doing so, the air will not gush into your cabin even if u r driving at fast speed.

[Dumb]

I am not aware much FC difference when aircon on or off[dizzy]

 

I am certain A/C on will surely affect FC. How? I dunno.

 

But whether A/C temp high or low will affect FC or not, I dunno. I can only guess it would as the engine has to work harder.

[Gabriel]

same here...

and beat those wannabes as well

[Zyrofillica]

okok now tt we are clear about the aircon. What about the radio and the fan blower? do these 2 take as much away from the engine as the compressor would? (usually my fan settings is lowest but my ICE is at max volume )