Air conditioning - Can't I turn it off and just get outside air?

Yes - do this:

Turn AUTO off.
Turn A/C off.
Select preferred fan setting.
Set temp to lowest setting (Max Lo or something like that).

 

What 'ny biker' said is correct.

Reducing the temp setting to LO makes sure the engine will not heat the air, and turning off the A/C button makes sure the car will not cool or condition the air.

 

Here is what I do.
1. Press climate button beside screen
2. Press desired fan speed
3. Select desired airflow, face level vent and fresh is what I normally select.
4. If AC button (top left of my 04 screen) has a bright green bar across the bottom press it.
5. Adjust temp with steering wheel buttons to minimum.

Because the Prius is such a slippery shape there isn't a lot of air flow through the vents without the fan, I always have my fan on low if I'm not using heating or cooling.

 

The Prius won't run the A/C compressor unnecessarily. When the A/C button is green, it just means the compressor is enabled, it doesn't mean it is running. Also, the Prius A/C compressor has an electric variable speed direct drive; it can run at any needed speed. If you leave your climate control on auto and set the temperature as needed, the Prius will do a good job setting the fan, compressor, and heat. A lot of people make it harder than necessary, and end up fighting the system. If it is cold outside, the Prius will not run your A/C compressor unless you have the temperature set to max cool or the humidity is very high and you need defrost.

Tom

 

good infos gbee, thank you

 

Yes, good info! Thanks!

BTW, I haven't taken a poll, but because of the font and underlining, a lot of people seem to misread Tom's "qbee" moniker as "gbee". Life is hard.

 

I'm used to it, but thanks for pointing it out. Gbee has a snazzy sound to it, like the Gee Bee racers of the 1930s. Those airplanes were pretty much all engine. Qbee comes from my nickname, plus the "bee" at the end of my last name.

Tom

 

Actually, by turning of the A/C button I increased mileage by about 5%. This indicates to me that the Prius is, indeed, running the compressor unnecessarily.

 

It shouldn't, unless you have the controls on manual. Otherwise it's strictly a function of the temperature setting and humidity.

Tom

 

I am in your area, so dealing with the same weather and temps. Right now Lola is showing 51.7 mpg on this tank. I turn off the AC and just run the fan. Even in the winter I do that and adjust the temp to a comfortable setting. The only time I use the AC is in the hot, humid summer. You know about that.
You will find that life with a Prius just keeps getting better and better as the price of gas goes up.

Donna

 

I'm an engineer. There are several (many) of us on P.C., and collectively we have spent a lot of time studying and experimenting with the Prius, plus reviewing Toyota's technical information. There are also a couple of Prius techs who contribute to the forums (and one Hobbit). It's really not all that complicated, and some of the information is self revealing when examined with a bus analyzer which shows the messages sent back and forth between the various controllers.

Tom

 

Thanks for this info - I just got my 2009 Prius on Monday last week and was wondering why the A/C was constantly turned on. So different from my Echo. LOL

 

Or you chronically have the temp setting lower than you need it. Raise it a little and that will shut off the compressor sooner. (Uhh... just as QB noted above.)