Originally Posted by Quicksilvers

DIY method you will never get all the transmission fluid out removing the drain plug. I would say it’s just about 3.8-3.9 quarts purchase 4 quarts you will use to refill your transmission back up with new transmission fluid.Yes the only possible way to remove all the transmission fluid in your A7 transmission would be to remove your A7 transmission from your 370Z and drain from your drain plugs and completely drain your torque converter or use a drain machine like the one’s you will find at your local Nissan dealership service department and they still can’t remove all the transmission fluid from the torque converter only some transmission fluid will come out. In total your A7 transmission holds about I would say 10.2-10.3 quarts of transmission fluid. The worst thing you can do is not change your transmission fluid because the fluid itself will degrade over time and get darker so you would have to do the drain/refill/drain/refill drain/refill method over and over again until your transmission fluid begins to come out clear which can be a pain. The Nissan transmission fluid that all the Nissan dealership service departments use is a semi synthetic type transmission fluid to last a long time. You can use any semi synthetic or full synthetic transmission fluid you choice. Nissan will never know what transmission fluid you are using. That is why I recommend using a higher quality synthetic transmission fluid like Amsoil or Mobil 1 etc. as long as you change your transmission fluid by 30K miles you should be fine. I change my transmission fluid every 2 years because the service on my Z is severe duty with track and street duty.