Anecdata: I turn my phone's wifi off when not required because it has a significant effect on the battery life - particularly when I'm not in range of a wifi signal. I've had a full charge die on an 8-hour country drive because wifi was on. On the return trip, wifi was turned off and it behaved as expected.
Go for a long walk in the park? All that time your phone's wifi is straining to find a wifi signal. It's not as big a power sap as the screen, however it's constantly, silently in use and the screen isn't.
Go for a long walk in the park? All that time your phone's wifi is straining to find a wifi signal. It's not as big a power sap as the screen, however it's constantly, silently in use and the screen isn't.