G/f's '07 Impreza 2.5L non-turbo, 70K miles. ATF level is down a bit on the dipstick, maintenance history unknown, figured I might as well do a drain and fill. Owner's manual lists Subaru and Idemitsu ATF HP, along with Castrol Transmax-J and Pennzoil ATF-J - what readily available and reasonably priced fluids are you good folks using in these transmissions? And how much fluid will I get out just draining the trans (not doing a complete flush)? Thanks in advance for all responses.