When I got my 14 PM I noticed that 5G used more battery (as it did on my 12 PM), although it was much faster than 4G of course. I just left it on 4G. However a few months ago I switched the phone back to 5G as I was downloading and sending some large files. I didn't bother to change it back to 4G. Later I noticed that now it doesn't seem to use any more battery than 4G. I don't have any documented numbers for either though, just my observation.