"Prevent Auto Lock" Issues

You can manually dim the screen in the settings if you are going to have it on for a long time. Or you can just hit the little sleep button on to of the phone. It’ll still keep track of where you are, and give you TTS directions. You can always turn it back on if you need to look at the map.

This makes a huge difference in the temperature and the battery usage.

From what I can tell, “Auto-Lock” has to do with it “locking” to track your position on the map as you drive.

I don’t think so. Prevent auto-lock should prevent the display from automatically turning off.

That’s weird. I turned it off and it stopped following my car, and the screen stays on either way.