With iOS13, the Dark Mode came to iOS as well and the question
is, will it help improving battery run time on the iPhones as well?
Since OLED consumes more power when showing white screen,
the Dark Mode could be a game changer.

PhoneBuff has set up a test setup with two iPhone XS to perform automatized tests with Google Maps and compare how the Dark Mode will perform against the Light Mode on OLED screens.

The result speaks for itself:

It’s obvious, that the Dark Mode indeed saves power as less pixels have to be illuminated.

Here’s the Video showing the test in timelapse: