MCAT in-classroom classes may not be effective depending on the instructor, not sure how online classes run. We found private tutor (especially good one that has previous successful track records) much better, although they are expensive ($100/hr) but we only needed 2 sessions per week (each session can run 1-2 hrs). If your son has a strong science background (bio, chem, phy) then the tutor’s function is mainly keep everything on-schedule and help out the weak areas. One summer was all it needed to achieve 515 (practice FL tests were 510 + or - couple points). What FL (full-length) tests did your son try? We used Next Step and AAMC.