So, we are getting in to the hotter and more humid time of the year. When I drive home from work every day, I have my windows rolled down when driving through town at slower speeds. But once I get on the highway and start approaching highway speeds, I roll my windows up.
At this point, I press the A/C Econ button twice so that I have the A/C off and am getting air coming through the vents. I also set the thermostat dial as low as it can go -- 60. Obviously, I want the air to be as cold as I can get it without the compressor running.
But occasionally (most often when I'm going down hill) I will hit the Econ button again to turn on the A/C. I only run it while going down the long hills, just enough to get the humidity out of the cabin.
But am I costing myself a bigger hit on my MPG by running the A/C at 60 as opposed to something higher like 75? My understanding of the climate control system is that when the system is set to 60 there is no heat being directed to the cabin from the engine. I have found that to be true during the winter, and in the summer time this sounds ideal. It would be counter-intuitive to introduce heat into the cabin when trying to cool it, UNLESS you were TOO cold. Then I could see setting the thermostat higher -- say 75. Also, it seems that taking heat from the engine can only serve to make it less efficient. But is my logic wrong? Does the A/C system run full blast (at one temperature) and use engine heat to modify it? Or does the A/C system have the ability to fluctuate its cooling temperature independent of the engine heat? Or perhaps a third technique is used -- the A/C runs full speed when on but turns off for varying amounts of time to ensure that the cabin temperature is maintained?
Just looking to stay somewhat comfortable while minimizing my MPG hit this summer. Thanks for your input.
leave it set to 60. when you load the engine switch it to a/c off mode. if you set it above 60 it will just mix in warm air, but the compressor will still cycle as before. also, keep it on recirculate. that way when the a/c compressor is off (not contributing any cold) the fan will be circulating the cold cabin air, and not mixing in any outside hot air.
sounds like you are doing it right.
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2000 Silver MT Insight
WAI, HTR200, Kenwood MP3 head unit, 3 MTX stealth subs, very-high-mounted 4th brakelight, yellow-top, tinted, SG2, MIMA, center armrest.
You know, you really ought to see exactly how much of a mileage hit you experience when running the A/C. I normally don't run mine either, but it's been pretty hot here the last month or so. So I just figured screw it, I'm running the A/C and I'm going to be comfortable. With it in the econo mode, and careful driving, I've only see about a 3-4mpg hit. I'm still getting better mileage than any other car on the road so I'm going to go for the comfort.
-Don
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Iggy: 2000 Insight, 5-Speed, A/C, 112k miles -- Holmgren footrest, Armrest King armrest,
IMA battery, BCM & MCM @ 70k, O2 sensor @ 76k, Trans rebuild and clutch @ 94k
I doubt that it mixes hot air with the cold air to get the set temperature during AC usage.
The AC system looks at many variables when deciding what to do, including outside temp., the sensor on the front of the
dashboard, etc. It would be very stupid for the Honda engineers to consider all these inputs to design a strategy to cool with
efficiency, and then spoil it by adding hot air from the heater, no ?
I use the auto setting when at first, to do everything possible to cool the 140 F interior. ( with window open for first mile to
flush the hottest air ). I switch to econ later.
I also am not one of the kooks that sweats like an animal in order to keep milage number high. Arn't those the same guys that
snag traffic when driving 50 mph on the Los Angeles freeway system ?
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-Les
2001 5 speed 207K miles.
--- Google 'Peak Oil' and learn what may be coming too soon ---
I tried this method of getting the AC turned off and the fan going but when I set the thermostat to 60, or any cooler temperature for that matter, I get COLD air out of the vents even though the outside temperatures are in the 70s or 80s. I also notice that there is a load on the engine. So while there is no indication on the screen that the AC compressor is running, I am fairly sure it IS running. There is no way I would get cold air from those vents unless the compressor is running, unless Honda has figured out how to get cold out of the engine!!!
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Jim Isbell
2000, 5 speed, 250,000 miles
"If you are not living on the edge, well then,
you are just taking up too much space."
If the LCD says "ac off" then there is no compressor usage.
Unless you use the window defogger button (second button when view left to right - US models). That button when pushed will use the A/C compresser as well.
JoeCVT = Just your average CVT owner
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2004 CVT Red Insight (purchased May 2011)
Relocated outside temp sensor near mid engine
No other mods performed yet
2003 CVT Blue Insight
Modified version of MIMA_L (with foot pedal)
Automatic warm air intake (all season)
Low Speed Auto Stop (LSAS)
ABS - IMA regen enabler (allows regen during ABS)
Relocated outside temp sensor near mid engine
Cooling fans powered by 12V Solar Panel
2001 MT Blue Insight (purchased Nov 2011)
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Max MPG and A/C Set to 60 or Higher?
