ECO A/C Mode impact on MPG
 

So I have read a few threads ont he A/C and it seems that many say that ECO mode gives better MPG, but at what cost? Has anyone tried to determien the impact of ECO mode? And what exactly is ECO mode doing differently? I ask becasue I liek the interior temp cool. I typically leave my temp on LO and vary the fan speed. I have a TCH coming next week and am concerned that I may have to sacrifice comfort for MPG. My goal is to get at least 30-32 MPG consitently. In ATL the humidity is a killer, i will have tinted windows. I drive 18 miles each way to work in varied 40-60 MPH driving. Even in the AM the A/C is often needed for dehumidification, in the PM it needs to really crank for a while to get my cars comfortable, then I typically clcik the fan speend down to 3 out of 7, but leave the temp on LO. I use the recycle setting 95%. Are my expectations of 32MPG and a cool cabin unrealistic?

Re: ECO A/C Mode impact on MPG
 

You should be able to exceed 32mpg without problems even with the A/C running. Your drive is long enough (18 miles) to warm up the engine and get great mileage. I notice about a 3 mpg hit when I run the A/C in the afternoon. Mornings are high 60s to low 70s lately and I can get by without A/C. Keep in mind a temp of LO overrides ECO. You have to keep the temp 66F or higher to use ECO mode.

I find moderate acceleration gives better mpg than slowly accelerating. Try and conserve momentum, brake lightly and early if needed so regen captures most of the energy. If traffic allows it, let your speed build on the downhills, and slowly drop back to your normal speed going back up hill.

I had my windows tinted to help with the heat and really like the results. I don't even notice the sun on my arm anymore! I had Formula One Pinnacle 35% tint on the sides and rear. It blocks 50% of the heat and 99.5% of the UV. Great stuff.

Re: ECO A/C Mode impact on MPG
 

Get the car and enjoy it. The AC will not be a problem. I live in Tennessee and the AC cools the car very quickly and I have not put the tint on yet.

When you get the car put it in Eco mode and you will never know the difference. I have no idea what it does, but my car is cool w/ it on so I assume it is helping the MPG and to me it doesn't cost me anything.

Also w/ the length of your drive and the reasonably high speeds your mileage will easily be over 32. I am getting about 37 in my 5 mile commute that never reaches highway speeds (usually less than 35 mph). On the highway I usually get 40+ mpg.

Re: ECO A/C Mode impact on MPG
 

I believe the ECO mode causes the A/C compressor to run strictly on the batteries rather than the engine.

Re: ECO A/C Mode impact on MPG
 

The absolute worst case mileage I can get with the TCH is 36. This means full AC, full electronics, lights, everything, at 80+ MPH. I have never seen it go below that consistantly (obviously going uphill and accelerating temporarily drives it down to the 10MPG range, but that is balanced out by 60+ periods going downhill or flat)

Re: ECO A/C Mode impact on MPG
 

We have been having 86 to 90+ humid weather in WV lately and I have not seen a loss of A/C effeciency while in the ECO mode. I'm not sure why you'd run it in anything else. Then again I guess if you're really watching the screen closely and if you notice that the ICE is driving both the wheels and charging you could switch the ECO off and utilize the excess hp from the ICE to drive the A/C and save some of the discharge from the battery. I'm not sure what that would really help but I guess someone on here will.

I'll continue to drive in ECO.

Re: ECO A/C Mode impact on MPG
 

The TCH A/C compressor is electric and run off the same high voltage system as the motor. There is no belt or physical connection between the ICE and the A/C compressor. The ICE powers the compressor by charging the batteries. I believe ECO changes the cycling of the A/C to longer cycles (both on and off.) Really spiffy system, and totally cool (pun intended) for the A/C to work even when the ICE is off.

Re: ECO A/C Mode impact on MPG
 

I do find it anoying that the ECO switch is hiding to the left of the steering wheel. What's up with that?

Re: ECO A/C Mode impact on MPG
 

It's right next to the fuel filler door release button. They put it there to make it easy to accidentally shut off ECO mode when you go to fill up.:shade:

Re: ECO A/C Mode impact on MPG
 

I found the opposite. It's there to get you to press the fuel filler door button when you mean to push ECO. I did it twice the first week I owned the car!

Re: ECO A/C Mode impact on MPG
 

I like it in an obscure place out of the way b/c I don't ever intend to touch the button again.

Re: ECO A/C Mode impact on MPG
 

I was driving thru Atlanta yesterday and temp on the thermometer was 102. Air on ECO mode nice and cool with tank average above 42 mpg. No sweat!!

Re: ECO A/C Mode impact on MPG
 

Yeah, I'm in agreement with you. I run with the AC on all the time and I just leave it on the ECO mode. I find that the car cools down rather quickly.

Re: ECO A/C Mode impact on MPG
 

Well I got my TCH Titanium yesterday and the AC is awesome, I have never had a car wih such strong AC. I have not really run in ECO much as it does seeem to take much , longer to cool the cabin. I will get my tinting Monday and hen my try ECO mode. Thisis the first car I actuall have to turn down the AC otherwise it freezes me out.

Re: ECO A/C Mode impact on MPG
 

As a technician at an independent shop I have driven all makes and models and Toyotas always seem to have the coldest A/C, no matter what model.

Re: ECO A/C Mode impact on MPG
 

Generally this is true, but if you (or a passenger) adjust the temperature to HI or LO the ECO automatically turns off.

I HATE that they placed the ECO button next to the fuel door button - it should be part of the climate control system since that's what it controls. But more importantly I feel that the fuel door button should be inactive if the car is moving or out of Park.

I still haven't been able to find an absolutely definitive explanation for what the ECO button does and why it deactivates when the temp is moved to HI or LO.

Re: ECO A/C Mode impact on MPG
 

OmegaOmega — Have a look at pages AC-27 to 30 of the attached file from the TCH Repair Manual for a description of precisely what the ECO button does.

Stan

Re: ECO A/C Mode impact on MPG
 

Unless you need the de-humdifier, or aim the air the the defroster vents while cycling through the options of discharge points, or turn it to LO or any of the other things you can do to override the ECO mode. I wish the ECO would automaticly turn back on when it gets back into a setting it will work in. Just remember if it was on, put it back on, if it was offf, leave it off. I don't know why it is not smart enough to remember.

Because of that I hate that the switch is hidden. I am obsessive compulsive about being sure it is on, and I hate a hot car. I have found th when driving in direct sun, I set the temp to 75 and auto and if not in direct sun, I set it to 78. it keeps the car plenty cool. I bought an automatic climate control system so it can do it's job. No sense trying to do the job for it.

Re: ECO A/C Mode impact on MPG
 

I wonder how many people are aware of this little piece of information regarding ECO mode.
Page AC-28 of the attached PDF file.

"During cooling under ECO mode control, the
cabin temperature is maintained at 25°C (77°F)
even if the set temperature is below 25°C (77°F).
Since the power consumption of the electric
inverter compressor is limited under ECO mode
control, this does not indicate a malfunction. To
decrease the cabin temperature to below 25°C
(77°F), the MAX COLD temperature (18°C (64.4°F))
must be selected or ECO mode control must be
canceled by turning the ECO switch OFF."

Re: ECO A/C Mode impact on MPG
 

I read that, and thought, "there must be some mistake" because I use eco mode all the time and if my car gets anywhere near 77 degrees, it is much to warm for my liking. I have gotten into a 90 plus degree car and in a matter of a very few minutes, am driving at a very comfortable temp,. If it is not below 77 degrees I will stand corrected, but I don't think so. I set the left and right temp. to 73 or74 and just let it do it's thing. The air coming out of the outlets seems very cold, and the fan speed slows down rather quickly. By the way....If I feel a little to cool, I will raise the temp. to 75 and the fan speed will lower, and the temp. will raise eventually. Does this mean it went up to 78? Not being argumentitive, just my thoughts.

Re: ECO A/C Mode impact on MPG
 

Stan - Thank you for the attachment... it answered a number of questions... and created a few more; some I'm hoping you can answer...

The diagram shows the basic design of a neural network controller that interprets multiple inputs/sources of heat to help the system determine the true ambient and/or desired temperature setting input by the user. Is this something that exists in all 2007 Camry Hybrids? If so, is this proprietary to the Camry line or at least the Camry Hybrids? Or is this a standard auto a/c system?

With the Ion air cleaner; does this require any maintenance? If so, is it automatically performed by the dealership when you take it in? I have to clean my home ion purifiers about every 3 months - but I see no maintenance/care information listed in the standard manual or in your PDF you attached.

Also (and this is more speculative), since the ionizer is only in one vent, is it prudent to have cabin air always set to recycled vs. outside air? This way you would avoid bringing in air through other vents that cannot charge the ions... Or - above all else - is the ionizer simply there as a 'gimmick' and remains too small to truly be effective at charging enough ions to filter the cabin air?

Re: ECO A/C Mode impact on MPG
 

I believe the ions will fill the cabin air so as long as the driver's vent is not closed, you'll be fine. It doesn't filter at the vent itself.

Re: ECO A/C Mode impact on MPG
 

I've noticed the same thing. It makes me wonder if my ECO mode is actually doing anything. I have not noticed a real difference in cooling capability (or heating) regardless of whether it's off or on. I still turn it on mind you....

Later!

Dang

Re: ECO A/C Mode impact on MPG
 

My interpretation of the 77 degree limit, based on page AC-30, is that at 77 degrees and above the compressor will run at nearly full effort (C2 in the figure) to lower the temperature to the setting (no matter what the setting is, except for MAX COLD which stops ECO mode) , but when the temperature is less than 77 degrees the compressor output is radically reduced so that in conditions bright sun or high outdoor temperature the cabin temperature might not reach the desired setting.

In any case this is an incredibly sophisticated system! Come Winter we can discuss how clever the heating system is and the effect of the ECO switch in the cold. :)

Re: ECO A/C Mode impact on MPG
 

Well, since you ask, here are my thoughts.

• I think that the temperature you feel depends on both the actual air temperature and on the air flow velocity past your skin — the "coldness" you feel is determined by the rate of heat removal from your skin, which depends on both these parameters. I suspect that it just seems warmer when the fan speed drops, but that the actual air temperature may be the same. The simplest way to find out is to use a thermometer at the vent to measure it!
• I think that all the current Camrys that have the dual-zone climate control system use the same neural-network controller. I can't speak about whether other manufacturers also use neural-network controllers, but I wouldn't be surprised if they did.
• The PlasmaCluster system needs no maintenance. It's not like a normal electrostatic air cleaner. The latter charges the air molecules (usually negatively). They then stick to particulates and other large molecules in the air and so precipitate them onto the metal collector nearby, which then has to be cleaned periodically. They also spew a net (negative) charge into the room, and may also generate some ozone. The PlasmaCluster generates both positive and negative ions in equal amounts, so that the emitted air is neutral, and essentially no ozone. There isn't any significant precipitation of dirt on the driver's-side vent, in my 1-year's experience. (I also haven't been aware of any smells, or of the associated "noises" that they tell you about.) It seems to work effectively and innocuously.
• As long as the driver's-side vent is open, the system should work whenever the ventilation fan is "on."
• I think that page AC-30 shows that the cooling effort ("C2") expended in ECO mode is greatest when the cabin temperature is highest ("T2" is well above 25 degrees C, I think), and progressively reduces A/C power consumption as the cabin temperature drops. When the cabin temperature is 25 degrees C or below ("T1" on the graph), the A/C is at its lowest power consumption ("C1") when ECO is "on." If you request a lower temperature than 25 degrees C, you won't get it with ECO "on." At least, that's how I interpret it.

Stan

Re: ECO A/C Mode impact on MPG
 

On my way to work this morning, i put a termometer int eh ac vent.

I had the co switch on the whole time.

Temp was set to 70, and the discharge air was 60 when moving, and 65 at a stop light.

Then I changed the temp to 75, and the discharge temp was 65 while moving and 75 at a stop light.

Then set the temp to 76, and the discharge temp varied between 70 and 75 while driving.

Re: ECO A/C Mode impact on MPG
 

But you might get it if the outdoor temperature or sun load is low enough. Basically ECO will run the AC at reasonably high power to get the temperature down to T2 (so you don't burn up in the heat) but slacks off for lower temps so you might not get them.

Re: ECO A/C Mode impact on MPG
 

But it is important to know what the outdoor temperature was. If it were 100 degrees, you probably wouldn't have gotten that discharge temp at least after the temperature stablized. However if it were 80 degrees it probably would. In my case this morning, the heater ran and I would have had no problem maintaining a 60 degree discharge temp with the AC off. :)

Re: ECO A/C Mode impact on MPG
 

I put a dial temp gauge in the center vent about 2 weeks ago to see what the AC temps are doing. I don't care for the fan noise, so I usually don't have it set for auto. The past week has been a cooker with temps running around 97 to 100F on my drive home. I've been running the AC set to 78F with ECO on. I found the vent temp dropped to 40F for about 10 minutes, then slowly went up to around 55F as the cabin cooled down (with the fan set for 4 bars.) Nice!

Re: ECO A/C Mode impact on MPG
 

talmy — I buy that! The maximum power used by the A/C is more limited in ECO mode; but, if the outside temperature (plus heat load caused by sun on the windows) is not too high, you might indeed be able to get below 25 degrees C even with ECO mode on.

Stan

Re: ECO A/C Mode impact on MPG
 

Yup, On the way home mine went down to 40 degrees F. (Ihad eco on, a/c set to auto and 78 target temp. It decided to utilize recirc.)

This morning it was about 80 degrees F.

When I got in the car this afternoon the thermometer read 130 degrees F.

The exterior temp was around 90 degrees F.

I wonder what that 130 temp does to the battery?

Re: ECO A/C Mode impact on MPG
 

ag4ever — 130 degrees F (~54 degrees C) isn't too bad, seeing that the NiMH battery is well insulated by its cover, steel casing, and plastic module cases, from the car's interior heat when it is parked in the sun for a few hours only. I'm pretty sure that the battery itself was a lot cooler than this, and probably well inside its "comfort" zone.

Stan