Climate Temp Setting Seemed to Reduce Fuel Economy with Auto Turned Off

[Shawn Clark]

I always run with the fan set to 1 or 2 or off. I don't trust auto.

[cycledrum]

Originally Posted by Shawn Clark

I always run with the fan set to 1 or 2 or off. I don't trust auto.

If running A/C at low fan setting, is it less strain on system to select recirculated air? (since it won't have to cool hot outside air)

I know this has been asked in other threads. My '88 pickup owner's manual says recirc should be used when cooling cabin down, then use outside air.

I know the Prius auto system uses recirc for low temp settings, but switches to outside air at higher temp settings.

[alanh]

There's actually several degrees of "auto" -- air conditioning available or not, fan speed, and temperature. Each can be turned on or off individually -- in full auto, the computer controls all of them.

1. Manual fan speed: set a fan speed.
2. Manual A/C: deselect A/C button, A/C won't come on.
3. Manual temperature: set the temp all the way down to "LO", heat won't come on.

If you do all three you get a "vent" setting where it doesn't do anything but blow the fan at the speed you select. No heat, no A/C.