A/C Recirculator Automatically Turned Off (not in Auto Mode)

[R01k]

Today I was driving with the A/C in manual settings and the inner recirculator on. Eventually, the temperature outside decreased a little in the evening and I noticed how the the A/C put itself in external air circulation mode. This was surprising taking into account that the A/C was not in Auto mode. Could this be a programmed behavior to increase fuel efficiency somehow?

[cookiemonster]

From the u.S. manual: "When the air conditioning turns on, the air selection is controlled automatically. When the air conditioning turns off, the air selection automatically goes back to the outside air position."

Was it also set to defrost? If so, "While the mode selection is set (defrost) position, the air con- ditioning compressor will run automatically. The outside air position will also be selected automatically."

[R01k]

I see. I haven't gone over the entire User Manual yet.

Thanks!