Yeah I've always used the EGT meter to fly the airplane at ~75°F rich of peak.
However a SR22 pilot suggested that I could also try flying it at around 1370°F, since the SR22 has the best economy at that temp. Apparently the SR22 and R172K have very similar engines (basically the same according to him) so I'm curious to see if my usual mixture setting gives the same temp as the SR22(@ 20in MAP)