Hello I have a 2004 Honda Civic and would like to change the ATF fluid. The owners manual lists Honda ATF Z1, so I guess I need to go to the dealer? I was at Walmart today and I saw Mercon V ATF and on the bottle it mentioned that it meets Honda Z1 Is this ok? Or do I need to use the Honda fluid? Is there a big deal, I don't want to do anything foolish, however I don't want to pay extra for Honda ATF unless I have to.