[A] You may/might as well ask him = It would do no harm to ask him ; She said I might as well ask him ; He may as well come with me ; As there isn’t anything more to do, I may as well go home early.
[[A] may/might as well + infinitivo puede expresar un consejo muy poco enfático. La forma puede usarse con la tercera persona; y el hablante puede usarla con respecto a sí mismo.]
A Practical English Grammar (A.J. Thomson & A.V. Martinet) 