If you did water changes it would live....but it would be far from happy.imo a 120 wide 4x2x2 is the prefect oscar tank,for 1.you can also keep smaller tank mates..i had a 13" oscar in a 90 standard 4x1.5x2 and it didnt look right,so I upgraded.
min 75 to 90.but i wouldnt keep an oscar for...