AC always on

[regularguy]

Has anyone noticed that the AC on the Civic is always on when the climate control is on auto, regardless of the ambient temperature? Over the past few months I've noticed that regardless of whether it's 30 or 90 degrees outside, and regardless of the temperature setting, the AC compressor seems to remain running. I can only hear it spin down when I turn it off from the Climate menu, or turn off the fan altogether.

It does this on both of our Civics. I've been able to get my gas mileage average up at least 3mpg by manually turning the AC off when I don't need it.

Is this normal behavior? Am I prolonging or shortening the life of the AC by turning it off manually?

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[messenio]

Yes it's normal, and pretty common for a lot of cars from what I've heard actually.

 

[bonne]

Has anyone noticed that the AC on the Civic is always on when the climate control is on auto, regardless of the ambient temperature? Over the past few months I've noticed that regardless of whether it's 30 or 90 degrees outside, and regardless of the temperature setting, the AC compressor seems to remain running. I can only hear it spin down when I turn it off from the Climate menu, or turn off the fan altogether.

It does this on both of our Civics. I've been able to get my gas mileage average up at least 3mpg by manually turning the AC off when I don't need it.

Is this normal behavior? Am I prolonging or shortening the life of the AC by turning it off manually?

My experience tells me to leave it on except when you drive with open windows. AC will help you get a nice climate in the cabin and if you do not run the AC over a long period, it will wear out fast because of sealings not getting any oil from the AC liquid.

Regards, Lars.

 

[fjrman]

The Civic has a variable displacement A/C compressor. This compressor can deliver an output stroke in a range of 0 to 100%.

The benefits of this compressor are:

* Better acceleration and fuel economy
* More stable engine idle, less noise and vibration
* More consistent temperature output

 

[regularguy]

The Civic has a variable displacement A/C compressor. This compressor can deliver an output stroke in a range of 0 to 100%.

The benefits of this compressor are:

* Better acceleration and fuel economy
* More stable engine idle, less noise and vibration
* More consistent temperature output

Thanks! Searching for that brought up this older thread which I did not find before posting. Sounds like a great idea, but in my experience it seems like the AC is hogging power when left on continuously. My gas mileage used to be 38-39 for my typical commute (averaged over several months), but for the past 2000 miles since I started turning off the AC manually, my average mileage is up to 42.7.

I've been turning the AC on maybe twice during an average 10mi commute. Any opinions on whether cycling the clutch this way will lead to enough wear to end up costing more than the gas savings?

 

[BriteBlue]

Years ago the AC compressor probably had a more significant effect on gas mileage than it does today. Most things I've read during the past 10 years or so say it more efficient to run the AC & keep the windows rolled up than to drive with the windows down which increases the wind resistance.

 

[civilian]

AC compressor is vital to keeping your windows clear in high humidity, even in winter.

Just hit AUTO and SYNC and leave it there. Spin the temperature knobs to a comfortable level in summer and winter and don’t mess with it manually.

 

[fenix-silver]

Years ago the AC compressor probably had a more significant effect on gas mileage than it does today. Most things I've read during the past 10 years or so say it more efficient to run the AC & keep the windows rolled up than to drive with the windows down which increases the wind resistance.

Absolutely more efficient to run the AC than to have the windows down at highway speed. Fun anecdote: back in my WRX when I was doing an e-tune I had to do 3rd gear pulls (it had the 4 speed auto) to do logging, which took me to scary fast speeds (~130 mph, and yes, that was a bit gnarly in that car). During one pull I had it floored, but the car stopped accelerating maybe around 115. Realized after I let off that I had the windows down.

 

[CivicXI]

Absolutely more efficient to run the AC than to have the windows down at highway speed. Fun anecdote: back in my WRX when I was doing an e-tune I had to do 3rd gear pulls (it had the 4 speed auto) to do logging, which took me to scary fast speeds (~130 mph, and yes, that was a bit gnarly in that car). During one pull I had it floored, but the car stopped accelerating maybe around 115. Realized after I let off that I had the windows down.

You should try driving out west. I was in Montana and I was holding 130mph for like 10+ minutes at a time in an Audi. There was literally no body on the road as far as I could see on the horizon.

 

[fenix-silver]

You should try driving out west. I was in Montana and I was holding 130mph for like 10+ minutes at a time in an Audi. There was literally no body on the road as far as I could see on the horizon.

Yeah, I've been out west in the mountains, but never really anywhere with the long flat straight stretches in the middle of nowhere. If I recall correctly, doesn't Montana or Wyoming have sections of roads with no posted speed limits?

 

[CivicXI]

Yeah, I've been out west in the mountains, but never really anywhere with the long flat straight stretches in the middle of nowhere. If I recall correctly, doesn't Montana or Wyoming have sections of roads with no posted speed limits?

I think they used to have no speed limit but the federal government made them put in a limit but they didn't really enforced. I heard for a while it was a $5 fine you could pay on the spot and people would just keep a wad of $5's in their car. I mean, the whole state looks like this on the interstate. It's pretty easy to keep your foot buried for like an hour straight. Apparently the A5 tops out at around 130 with the motor at 2900rpm in 7th and it's quieter than my Civic at 80... quite a car.

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[BriteBlue]

Years ago I got stopped in Wyoming for doing 91 in a 75 zone. I slowed down coming over the top of a hill but obviously didn't slow down enough. There were two police cars at the bottom. The ticket was over $100 at that time.

 

[CivicXI]

Years ago I got stopped in Wyoming for doing 91 in a 75 zone. I slowed down coming over the top of a hill but obviously didn't slow down enough. There were two police cars at the bottom. The ticket was over $100 at that time.

That's not too bad.. I had a 97 in a 65 zone a few years back. Cost $675 for my lawyer to bury that one to keep my record clean.

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