Originally Posted by
mike_one2many
IME (LAX-EWR), the only real chance of an upgrade is a Y- or B-up, and, occasionally, M-up, on some evening and red-eye flights.
Not sure they'd let it clear with miles if they're not letting Y's upgrade automatically.
Why would a M-up be any more of an occasion than a B-up? They draw upgrades to ZE from the same fare bucket.