does using climate control affect my mpg?

[audi_driver]

Just wanted to know if climate control waste's petrol? In my car there is no switch for heating or air con. I know that using the heater doesnt effect my mpg, but what if i turned my climate control to the coolest setting, is that considered as air con? and will that use up petrol?

 

[block]

If your climate control has an econ button on it, then pressing this turns your air con off, otherwise its on all the time. Thats how it is on the s3 anyhow. You might notice a small gain in mpg on a long trip but nothing substantial.

 

[mitch78]

:thumbsup:

 

[h5djr]

The only part of the air-con system that will affect the mpg is the compressor, which is driven by a belt from the engine. This has an electric clutch and the clutch only engages when the system asks for cold air. The rest of the time it just acts like a free running pully.

As mitch78 says, even when the clutch is engaged it affects the mpg no more than driving with the windows open. I leave mine on all the time, summer and winter.

 

[SteveTDCi]

I leave mine on econ its making a small difference , mines down to 34mpg which isn't good for a diesel.

 

[Matt]

Mine is never off. Still averages mid 40s with it on which suits me fine

 

[audi_driver]

I never realised what the econ was for until now, thanks! What happens if i turned off the econ button but still set my temperture for cold air? I wouldnt lose mpg cos Im not using air con right?

 

[David]

If you turn the econ button off, then you will have the ac running... So as said, you won't notice anything different.

 

[audi_driver]

cheers, thanks for all the replies

 

[benw123]

A/C can add as much as 10% to your fuel bill, although few people notice it. My Prius has an electric A/C unit (i.e. it's not driven from the engine), but fuel economy does worsen if I use it.

 

[biggiep]

I find about an 8mpg swing with climate control on for the same 400 mile trip

 

[mechanic69]

I've been running with mine off for the past couple of months and I'm seeing a 4mpg difference. My trips are mostly short and it does make a difference. You might as well keep it off if you're not using it.

 

[h5djr]

It depends on the weather and the temperature you want for the inside of the car. The compressor is not being turned by the engine unless cold air is being requested by the climate control. In that situation it's just a free running pulley.

If the weather is cold and you are adding heat to the inside of the car then again the compressor is not being engaged as the sytem is not asking for any cold air and therefore no extra load on the engine.

If the weather is warm or hot and cold air is needed to cool down the interior then the compressor is engaged and will add a slight extra load to the engine and slightly less mpg. But that's the whole purpose of having air-conditioning in the first place.

The Econ button stops the climate control from engaging the clutch on the compressor and so no cold air can be provided.

I have mine on all the time and let the climate control decide when cold air is required by setting the appropriate temperature for the car interior and I still get 43-45mpg from the 2.0TDI-170.

 

[lil_coz]

I've heard you can lose as much as 15-20% in economy if the AC is running. It is fact that you do use more fuel, and it saps some engine power too. I think as a rule of thumb, if you're travelling at under 50mph, you're better off with the windows down. Above that, the drag gets so much that you then become better off with the AC on. I have mine on every now and then. Just to keep everything in top shape. If you dont use the AC for a while, then the seals start to go and you lose gas.

Coss

 

[Khufu]

Yes, you will loose few MPG, but not using it regularly will cost more in maintanance due to leaks etc as mentioned above. Once a week, keep it sweet