Does leaving the a/c on under Auto all the time make the car use up more gas? I've heard ppl say this before. Is it better to just leave it off?

 

You do use more gas when running a/c. I think on most new cars, it'll hit you for about 1mpg. I don't use the a/c unless it's hot outside or raining.

 

I leave the AC on all the time, summer and winter, other the car fogs up really quickly.

 

Yeah, what he said.

If you open the moonroof or crack the windows you can turn the A/C button off or the whole system off. In Texas we get a few chances at that in March, April, Oct, & Nov.

 

I believe that the A/C light being on just means that the car can use the A/C if the climate control feels it needs to cool down the cabin. It does not mean that it is necessarily using the A/C at all times.

I know I have had mine on for pretty much all of the year I have had my G. I just set my desired temp and let it do the work. It has worked fairly well overall.

I get between 20&22 MPG.

 

When you hit auto the A/C goes on so mine is on all year long.

 

The AC will run all the time as long as the temp is above 25 deg. F or so.

I run mine only when needed (to cool the car) or if the windows are fogged up.

Normal warm and cool airflow from the car seems to work fine at keeping the windows clear if its not raining or snowing.

 

This is true. It willl run all the time above freezing temps. I usually keep mine off but sometimes turn it on for a few minutes or so. Our AC is a variable type so it should run at a very low level when not really needed. This is great as opposed to the old systems that cool the air and then heat it.

In any event, I did read an article that said most manufacturers see much better AC reliability when the system operates a lot due to the new auto climate systems. Don't forget when the system is running it is circulating lubricant as well. This helps to keep all the seals well lubricated and prevents them from drying out. Whenever I hear of someone having AC problems they are usually the same people that almost never use AC. I would suggest letting the AC run a few times a month at least.

 

I've found the auto climate system works better if I just leave it set at 70 (in the winter) and let it do it's thing. It seemed wrong to me at first when the A/C light came on when it was chilly out, but it looks like it's operating fine either way.

 

so the concensus is it doesn't really matter much either way? I'm mostly looking out for my fuel consumption, it's ridiculously high since I got the car 2 weeks ago.

 

Things like properly inflated tires, smooth driving, etc will have a much bigger impact than leaving your A/C on.

 

I read somewhere that AC use can reduce fuel economy by 20%.

 

Will I save anything if I turn the climate control on but the "A/C" button off for heating purpose during winter?

 

That's probably a gross exaggeration. In Edmunds.com's opinion, running with the windows down might actually be worse on mpg than the AC

Think Before You Vent(ilate)
Running your air conditioner does cause your vehicle to consume more fuel, but driving with your windows rolled down can be even worse due to the increase of drag on the vehicle. If you are driving slowly, such as around town or in city traffic, then you are better off leaving your windows open, if at all possible. For highway driving, roll up the windows and turn the air conditioning on.

Top 10 Tips for Improving Your Fuel Economy

 

Driving with your AC on is more fuel efficient then driving with your windows down.