Most of the time there is a 5 to 10 second delay. However, if I am in an area with a weak 4g signal and I have the phone set to CDMA/LTE mode, it takes a bit longer.
There is also an option to have the wireless data turn off only after the screen is off AND no motion has been detected for a few minutes.
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Thanks Deron, the delay is what I was afraid of, I'll probably not take advantage of this due to the delay.