AC Climate Control - Performance & Mileage

[Figoian]

Question: Does the Climate Control in AC anyways effect in the Performance & Mileage in any way? Assuming, the Climate Control is placed to the Extreme Cold (Blue) will lessen Engine’s Performance and FE, compared to keeping it in Medium or Close to Red?

Experts, please throw your points.

 

[Marun]

Hi Bud,

I dont think so. Whatever the chillness may be, the AC will continue to draw power from the engine.

 

[vskauto]

Auto AC with climate control is a very good feature.

Normally when the AC is switched on, the driver puts it in max cool to bring down the cabin temperature. The knobs are later fiddled to control the temperature until an ideal position is reached. Normally the fan speed is set to 1 or 2 position and the temperature is set to full cool.

In an AC with climate control, you have to set the desired cabin temperature and let the mechanism decide how to achieve that and retain it. So there is no headache on fiddling with AC during the drive.

There is no savings on FE. Once the AC is switched on, the engine has to take that load. You have to manually switch off the AC occasionally to enhance FE.

 

[shailinder]

Auto AC with climate control is a very good feature.

Normally when the AC is switched on, the driver puts it in max cool to bring down the cabin temperature. The knobs are later fiddled to control the temperature until an ideal position is reached. Normally the fan speed is set to 1 or 2 position and the temperature is set to full cool.

In an AC with climate control, you have to set the desired cabin temperature and let the mechanism decide how to achieve that and retain it. So there is no headache on fiddling with AC during the drive.

There is no savings on FE. Once the AC is switched on, the engine has to take that load. You have to manually switch off the AC occasionally to enhance FE.

I agree with the statement. Moreover, frequent switching on and off also puts load on the engine. It is advisable that once a AC is switched off, it should remain switched off for few mins so that entire system takes a rest and restart from level ZERO. By switching off AC, one would get marginal improvement on FE (+ 1km).

 

[Figoian]

I agree with the statement. Moreover, frequent switching on and off also puts load on the engine. It is advisable that once a AC is switched off, it should remain switched off for few mins so that entire system takes a rest and restart from level ZERO. By switching off AC, one would get marginal improvement on FE (+ 1km).

@ Shailinder: Agreed.

Auto AC with climate control is a very good feature.

Normally when the AC is switched on, the driver puts it in max cool to bring down the cabin temperature. The knobs are later fiddled to control the temperature until an ideal position is reached. Normally the fan speed is set to 1 or 2 position and the temperature is set to full cool.

In an AC with climate control, you have to set the desired cabin temperature and let the mechanism decide how to achieve that and retain it. So there is no headache on fiddling with AC during the drive.

There is no savings on FE. Once the AC is switched on, the engine has to take that load. You have to manually switch off the AC occasionally to enhance FE.

@ vskauto: Agree with your point. My question is around Manual AC and not an Automatic one. What I heard was something about the AC Compressor Auto Cut Off. Once the cabin is cooled, the cool air gets inside the AC and if the desired cooling level is reached, the compressor would cut off automatically and gets on if the temperature is increased. And thats why its suggested to keep the blower in lower speeds (provided only front seats are occupied) as the cabin air would get back to the compressor quicker than its in high speed.

So wouldn't the compressor cut off helps lessening the load on the engine?

This is what I heard, and not sure how techical its true.

 

[mumbaikar]

so does switching the AC on and putting the blower on 1 or 4 consume the same amount of fuel?

 

[shailinder]

so does switching the AC on and putting the blower on 1 or 4 consume the same amount of fuel?

Well the answer according to me is yes. Because blower is nothing but a fan and throws air, chilled or otherwise. So blower speed would not impact FE or not much.

Others, please share your thoughts.

 

[powerpacked]

Well the answer according to me is yes. Because blower is nothing but a fan and throws air, chilled or otherwise. So blower speed would not impact FE or not much.

Others, please share your thoughts.

Cut off temperature plays vital role here

With AC on and fan speed 1 will take more time to achieve the cut of temperature than as compared to AC on with blower speed 4 .
Faster the cooling rate earlier the cut off temperature.
This logic says that blower speed may impact on FE but should be very minimal.

 

[Surfer]

It all depends on the temperature settings, outside temperature, current cabin temperature.
If you set 20 it will take more time to cool if the current temp inside cabin is high.
Job of auto AC is to maintain the temp at particular level.
So whether its auto AC or manual it will affect FE. Cooler the temp you want lesser FE you get.

 

[vskauto]

AC blower speed - Performance & Mileage

so does switching the AC on and putting the blower on 1 or 4 consume the same amount of fuel?

In maximum cold set-up, AC compressor cuts off when it reached 8 degrees temperature. Well that means, the air passed through the blower will be cooled till 8 degrees. The cold air when mixes up with cabin air (which is warmer), the resulting temperature will be much higher.

When the blower speed is high, the air passed through it is less colder and takes more time for the compressor to cut-off. When the blower is set to lower speed, the air gets cooler fast (at sensor) and the compressor gets cut-off quicker. This is why the blower set at lower speed will result in a very marginal decrease in engine load, which gives better FE. Now it is same as travelling single or double. When law of physics is applied, two passengers should take more fuel that single passenger.

So the direct answer is "Either use AC or Or don't use AC".

 

[Prads]

As far I have noticed climate controls in cars like swift usually has the compressor switch off & just the blower running for sometime as the temp is reached(Dont really like that though),so mite give your engine less load sometimes,other high end cars the compressor usually does not cut out even when the desired temp has reached as some cars have multiple climate control zones

 

[Figoian]

As far I have noticed climate controls in cars like swift usually has the compressor switch off & just the blower running for sometime as the temp is reached(Dont really like that though),so mite give your engine less load sometimes,other high end cars the compressor usually does not cut out even when the desired temp has reached as some cars have multiple climate control zones

Yes. My question is basically for such small cars (Swift/Figo Etc.).

 

[Prads]

Question: Does the Climate Control in AC anyways effect in the Performance & Mileage in any way? Assuming, the Climate Control is placed to the Extreme Cold (Blue) will lessen Engine’s Performance and FE, compared to keeping it in Medium or Close to Red?

Experts, please throw your points.

As your question is for small cars then yes your temp setting will affect the mileage(performance also)as your ac compressor will have to run for longer durations to keep the cabin at desired temperature if placed more towards the coldest setting,in such case should help if you have good sun films on the car.
Trust me a good sun film takes out alot of heat,i had front windshield sunfilm,when it was removed I could notice a huge difference in cabin temp!

 

[powerpacked]

Most important part is whenever AC is on for sure drop in FE

How much is the beyond our calculation.
Very general observation is 1to 2 km per litter. This may vary depending upon driving style and conditions.
I normally follow the technique compressor on and off instead of setting temperature knob towards red.
This works well in early mornings and after evenings.
When sun is on the top and in its high performance zone then my left thumb says ‘no’ to off AC switch.

But coming to point the Auto Climate AC gives you freedom to set the desired temperature.
So Auto cut off is for sure not ‘8’oC as compared to manual AC so it allows you to use fuel to run the car instead of using for AC.