Here is my last contribution to the cause:

 

In my dreams I get tanks like that .

 

Come on guys stop using that A/C!

 

That's freakin nuts, man. The closest I've ever come to that (65.9mpg) is drafting trucks on the freeway.

 

Tom has it right.. cut back on the A/C while stuck in stop/go city traffic. It kills your mpg. It's been so hot around here that I've been using the A/C a lot more than usual but only when I know most of my drive will be approx 40 mph with few stops. I can actually keep the mpg up around 48-50. Once the car sits and idles with the A/C on, your mpg goes down the drain, then add E10 gas (a -5% mpg factor) and you're cooked....

 

So I guess that means it is normal. Any tips to adjust the A/C to not kill the gas mileage so bad when you have to do stop and go other than not use it? I think at 95+ that is not an option for my wife, lol. Is there any difference on manual A/C settings vs. Auto? Does it matter that much on the temperature setting? I have noticed that even set at 80 degrees it does not make much difference as the air feels cold.

 

I have tried varying temps and manual and Auto settings and haven't found any particular
setting helps better than any other. I have been using the AC only on afternoon
commute, I normally start first mile without AC due to stops at traffic lights. Once I
hit the hway I turn on the AC set at 80 then after several miles will set to 75.

One thing to work on is to increase the space between yourself and the auto in front,
that gives you opportunity to roll at 100mpg while the auto in front is breaking.
If timed right forward motion will start before you even have to hit the breaks.
That technique by itself should help presserve your MPG and should even increase
it. Same thing can be used when timing traffic light changes.

 

Yes, it makes a difference in several common scenarios. This is a topic that has been debated in this forum alot - please note that this is applicable to HCH-II's only.

The Honda Climate Control System implemented in our 2006 Civic Hybrids operates in three distinct modes - These get used depending on the climate control settings and the outside environment temperature. Let us just say, that if the outside temperature is either too low or too high, the Climate Control System's operation can only do so much to help your fuel economy.

Anyhow, the scroll compressor on our 2006 hybrids is actually a hybrid compressor that can operate as follows:
- Traditional belt-driven compressor (places load on the engine - hence low FE)
- Assisted belt driven compressor where the DC driven half provides assist.
- Purely electric operation (Places negligible load on the engine and ofers high FE).

Now, we want to be cool in a hot day, but do not wish to be impacted by lower fuel economy as much, right? Well, there are some things we may be able to do in most situations.

- Allow vehicle to cool off at first by lowering the windows before driving off.
- Buy a GOOD window mounted solar power gadget to help lower the inside temps while parked in the sun. The IMA power control module will refuse to operate if the cabin temps are too high (or too low).
- Maintain a good state of charge on your IMA battery. If the variables are played just right, the electric scroll compressor should happily hum along the majority of the time to keep the cabin temprature in check. Keeping a good state of charge is not that difficult. Please review Tarabell's article for some good tips.
- Keep the AC on automatic climate control. First start with a higher temp (for example 80-90 degrees) then lower it gradually to a confortable point. Please note that the blower fan speed is a good indicator of when the belt driven compressor kicks in. In other words, keep the fan speed from resembling a hovercraft and all will be OK. This is because the electric scroll compressor is only sufficient to maintain or correct slight temperature discrepancies.

Please also note that operating the AC in AUTO mode will enable to the climate control to remove air moisture more agressively thus allowing the occupants to achieve a good confort level at a higher temperature.

Finally, only in extreme situations will the belt-driven compressor start and there's very little we can do but to watch our FE go down.

Cheers;

MSantos

 

Running AC takes a certain amount of power. You can measure power several ways. We usually measure the power of the ICE in Horsepower but we tend to use Watts to measure electrical power. The important thing to realize is that Horsepower and Watts measure the exact same thing. 746 Watts equals one Horsepower.

It does not matter if you power an AC compressor from a belt or an electric motor. Both will put roughly the SAME drag on the ICE. The advantage of the electric is that it can be run when the ICE is off by pulling power from the battery.

 

Thanks MSantos.

I just went out and did some testing at 95 degrees outside after my wife came home. She had the Auto A/C set to 73 deg. and she said the car did not auto stop on the way home. I set the A/C to 86 drove a mile or so and then went down to 80. The Auto Stop worked every time. The car was actually very cool with the A/C set at Auto 80. I averaged 50.4 mpg on the 19 mile trip, but it was only through about 8 stop lights total. Do you have any idea at what temperature limits inside the car does the IMA cut off? Also how long does it take normally if you A/C the interior for the IMA to be happy again?

I have read Tarabell's article, but I am still not convinced if I agree with her acceleration procedure. I have tried the 2K RPM max method, but it seems like I hang in the low mpg range for a long time. I have tried to max out assist and get to 35 quickly (not floored, but more like 3K RPM) and the car seems to get into the power band quicker and then you can let off and max out mpg in less time. I have not done enough testing to side one way or the other, but getting out of the low mpg situation faster seems to work well. What procedure do you use for stoplights/acceleration from a dead stop?

Thanks again for your detailed post that helped a lot.