I bought 6 qts of merc lv and gave them to my mechanic to drain and fill my flex. he said only 4 came out. all the reading I've done here states that 5.5-6 qts should have come out. I suppose maybe it was low? I haven't checked it since I bought it in may. I told him we can do it again next month before I drive to fl, so at least more old fluid will get cycled out.