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Discussion Starter #1
In my quest for increased fuel economy, I've come up with an idea that I wanted to run by you guys...

"Economy" and "Economy+" settings for your air conditioner:

- Economy mode would only operate the compressor when the throttle input is at 0% for 5 seconds, regardless of whether or not you are in gear.
- Economy+ mode would only operate the compressor when the throttle input is at 0% for 5 seconds, OR the car is in Neutral for 3 seconds.

Of course, the ultimate question is "Will I save enough money (due to increased fuel economy) to pay for a new A/C compressor (due to the accelerated wear from the increased cycling) when that time comes?"
 

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Nice idea, but don't think the math would work out in you lifetime lol.

Sent from my SAMSUNG-SM-G891A using Tapatalk
 

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Oh, why not...let's give it a whirl!

I'm at about 6,000 miles, which clocks me in at about 2,000 miles per month, or 24,000 miles per year (80/20 hwy/city)
My average fuel economy, when I don't manually turn the A/C off while in gear, was about 27mpg.
My average fuel economy, when I manually turn the A/C on when coming out of gear, is about 32mpg.
Gas prices in my area stay around the $3.00/gal area, give or take 50 cents at different times throughout the year.
Long story short, at this rate I'll spend $2,250 on gas per year when implementing this method of only using the A/C when the engine isn't under load, whereas I'd spend $2,666 on gas each year if I didn't...a savings of $416/year.
It costs about $125 for an A/C compressor for the 2018 Mazda3.
I work at an auto shop where at least 4 people could replace this with no problem, for the fun of it (and a 12 pack).

At that rate, I could go through 2 compressors per year and still save money on gas!
 

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wouldn't that also cause your cooling fan to cycle on and off just as much as the compressor?

for AC compressor control, the only tuning program i'm used to (not mazda) only has a WOT cut, and a High temp cut. the only way i could see to do that would be to lower the TPS value so it thinks 1% throttle is WOT, but that is obviously not practical.

5 seconds is far too long of a wait, IMO. i usually end up at 250ms when i change stuff that i want to happen when i close the throttle. DFSO for example.

how do you intend to do this on your mazda? i'm new. just curious.
 

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to pay for a new A/C compressor (due to the accelerated wear from the increased cycling)
I'm not so sure this is a problem. The compressor already cycles a lot in normal usage, when it isn't that cold and it doesn't have to work that hard to maintain a set temperature. And the clutch is electromagnetic, so it shouldn't be affected significantly by more cycling.

Personally, I like this idea a lot. I'd love to have a mode that automatically turns on the compressor every time I'm coasting or braking to a stop, since that energy is being wasted anyway (in the case of braking).
 
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