Mike and Mizzou said it correctly. I only clarify that there’s an intrinsic difference between flac and MP3, in that the former is lossless rendering full quality, whereas the latter is lossy but has the advantages of a smaller file and more universal acceptance. Thus, seeking lossless MP3 is utopia or contradiction in terms.
In practice, unless you are particularly fussy plus endowed with sharp hearing plus using top hifi speakers, you won’t be able to hear the difference between the original and MP3 at 192 kbps. But if you want to also cater for differences that are mainly in the mind, then go for 320 kbps, in which case the file size will be about half to a third of the flac, which itself is half that of the wav.