Went to the mountains in our Prius

[pingman]

i just turn off a/c when climbing hills problem solved :P

[OlsonBW]

<div class='quotetop'>QUOTE(Spoid @ Aug 1 2007, 02:05 PM) [snapback]488858[/snapback]</div>

What do you normally get? I'm in Las Vegas, and my 07 Touring went from 46 to 42 when I started running the AC full time, and I bet my AC has to work harder.
[/b]

Here in Seattle I was getting around 51.4 mpg (55-75 degrees) and it quickly dropped to 50.3 (75 to 95 degrees) sparingly using AC (meaning until my wife really complains about it being too hot in the car - when she cools off I turn it back off again). If AC was kept on all the time we would be averaging at best low to mid 40s.

Keep in mind that there are no flat areas of Seattle and also that Seattle ranks as some of the worst stop and stay stopped and move a little, ok go, no stop, traffic in the country.

Forecast for the next 7 days is mid 70s to low 80s. It was 88 degrees yesterday afternoon. Yes, in Seattle.

[bmwquickspeed]

I wonder if this is something related to older Prius cars or maybe my battery is loosing capacity but on my car if I am lugging up a mountain I commonly see 1 bar.

I was never really concerned unitl I have noticed many saying that there battery never goes below 2 bars.

On the same subject I am also curious if anybody has seen no bars as I have never seen this condition.

When I get down to 1 bar you can hear my engine working much harder though.

[OlsonBW]

<div class='quotetop'>QUOTE(bmwquickspeed @ Aug 3 2007, 01:06 PM) [snapback]490110[/snapback]</div>

I wonder if this is something related to older Prius cars or maybe my battery is loosing capacity but on my car if I am lugging up a mountain I commonly see 1 bar.

I was never really concerned unitl I have noticed many saying that there battery never goes below 2 bars.

On the same subject I am also curious if anybody has seen no bars as I have never seen this condition.

When I get down to 1 bar you can hear my engine working much harder though.
[/b]

Unless you have over 150,000 miles on your Prius I wouldn't even begin to worry about your batteries (or gas engine for that matter) on your Prius. It's made by Toyota or conforms to Toyota quality standards.

[Presto]

<div class='quotetop'>QUOTE(bmwquickspeed @ Aug 3 2007, 01:06 PM) [snapback]490110[/snapback]</div>

I wonder if this is something related to older Prius cars or maybe my battery is loosing capacity but on my car if I am lugging up a mountain I commonly see 1 bar.

I was never really concerned unitl I have noticed many saying that there battery never goes below 2 bars.

On the same subject I am also curious if anybody has seen no bars as I have never seen this condition.

When I get down to 1 bar you can hear my engine working much harder though.
[/b]

If I leave my foot on the pedal going up the Coquihalla Hwy, the SOC drops down to 26%, which would probably be 1

[richard schumacher]

If the Prius cannot go to the mountain then the mountain must come to the Prius.

[zqfmbg]

Yesterday I was out with my wife on a little mini-roadtrip to Lafayette (we're in Fremont, so it's only about 30 miles or so away) and I encountered something that might be similar. The trip there was just fine, but when we got out of the car we noted the temperature differential between Fremont, which is near the bay, and Lafayette, which is pretty far up into the hills from Oakland and Berkeley. It can't have been more than 80 when we left Fremont but somehow it was in the upper 90s in Lafayette.

Anyway, we left going down CA-24 and the interior of the car was hot, so the Prius had A/C and recirc on. I think it was going down CA-24, anyway; it seemed like no matter how much I stepped on the gas (up to 3500rpm) the Prius couldn't keep its speed. I dropped from 53.3 to 53.1 mpg in a 5-minute stretch. I guess maybe in that area you are climbing a hill, since after a litttle while we hit the Caldecott and the real downhill portion and all of a sudden I was maintaining 75 even without warp stealth.

I'm going on a roadtrip up I-80 to SLC and beyond next week, so it'll be interesting to see what happens.

[Sufferin' Prius Envy]

<div class='quotetop'>QUOTE(jendbbay @ Aug 2 2007, 04:12 AM) [snapback]489154[/snapback]</div>

By the way, we did not experience such high external temperatures for the remainder of the uphill climb as the temperatures higher up were down into the 80's and even high 70s. [/b]

So let's see: Partway up the mountain you switched from recirc to fresh, and at the same time the outside temperature was dropping from 94 degrees down to the high 70s - and yet, somehow, you people are trying to attribute the additional available power to the dehumidification aspects of air conditioning?

IF changing from recirc to fresh had any affect on the car's performance, I doubt it had anything to do with dehumidification.
Dehumidification happens when warm moist air come in contact with the cold fins of the evaporator unit. This happens whether the car is in recirc or fresh air mode.

If anything, if we are going to try to attribute the increased performance on changing from recirc to fresh air, my guess would be the extra cool air being blown through the traction battery helping keep it cool. If you are forcing air into the car, it also needs to escape, and the traction battery vent is the most logical place.

By the way, do you remember hearing the traction battery cooling fan while you were experiencing sluggish performance?

Overall, I think the drop in outside temperature was the major factor in increasing available power.

[donee]

Hi Sufferin..

Who is insisting on anything? Your quote was not in the original post, or before any post I made. The system probably works to ensure comfort level. So, with lower temp, higher humidity might still be a net confort level improvment. AND, I did leave the posibility open in my post regarding thermal load change, without specifically mentioning it. That was in my thinking as a possibility when I wrote it. But, I wrote the comment as if the OP had been complete in her original description, and had told us the whole set of facts. Specifically, the temperature was still 94 F when she opened recirc.

Another thing is that the amount of water vapor air can hold at higher altitude and lower temperatue is less (in both cases). There is less water vapor in 70 degree 50 % R.H. air than 94 F 50 % R.H. air. So, flowing outside air inside would automatically dehumidify the cabin, not only by dilution, but difusion. Besides cooling the cabin air, as the outside air is now cooler.

So, dehumdification could still be the issue. As why did the AC still pull lots of power when the recirc was closed? If the air was cool outside, the thermal performance of the AC would have been allot better. But she reports only after opening recirc did vehicle power improve.

The AC could have still dropped out of dehumidification mode, and even turned the compressor off, as all cooling and dehumidification would have been provided by ventilation.

The hypothesis here is that an automatic dehumidication mode could still be the root cause of the high AC power demand in this case.

[Sufferin' Prius Envy]

<div class='quotetop'>QUOTE(donee @ Aug 5 2007, 04:08 PM) [snapback]491001[/snapback]</div>

The AC could have still dropped out of dehumidification mode, and even turned the compressor off, as all cooling and dehumidification would have been provided by ventilation.
The hypothesis here is that an automatic dehumidication mode could still be the root cause of the high AC power demand in this case.[/b]

OK, that makes sense too . . . BUT . . . the OP was driving across the Sacramento/San Joaquin (pronounced Wah-keene) Valley and into the Sierra during the summer . . . an area of the country know for its low humidity - especially on the days when the temperatures are in the 90s or 100s.

In high humidity areas, I could see where leaving recirc on would make sense.

I normally run the AC at about 80 degrees, fan on fairly high, and fresh air. To me, that is more comfortable than having slower moving very cold air blowing from the vents . . . but I don't know what would be the best settings for high temperature, high humidity areas . . . never been there in a Prius.