Stereo or mono when saving files

I have some wave files that I have saved in stereo. Would it be better to same them as mono in order to save space? Would I lose any audio or will mono blend the two stereo channels?

Thanks for the advice ahead of time.

I am digitizing all of my LP’s (around 5000). I am saving them as one long wav file so that if I ever need to extract songs from the file and export as mp3, I can do it.

LPs are usually stereo, so I’d leave them as stereo recordings.