As BucikGN I believe it was said doing an ATF fluid swap when you do it all( ie; not just 7-8 qts with a pan drop = a waste of time IMO ) is big money. I always do a flush then drop the pan to clean it and change the filter(s), then top back off. Only way to really be sure it is a full swap of fluid if you want to do a filter swap as well.
Costs me about $11 p/qt for RP. So thhat means I need 16 qts for the flush machine + 8 qts for the top off after dropping the pan and changing the filter = 24 X $11 = $264 for fluid. Labor/flush fee + filter kit = $160. Total for complete ATF service = $424!
Amsoil ATF in a 91 Caprice with 700R4 transmission. 140k miles on fluid (270k on original trans) and still looks, smells, and performs like new. Has large aux cooler and also an aux cooler line filter. Used for some towing.
No intentions to change fluid anytime soon.
Mazda CX7 requires Mobil #3309/T-IV and that is what I use. I will not accept a non "approved" universal fluid if I can. I feel that the approved fluid for any transmission is formulated on the best for the application and "suitable for use in" is not formulated to the be the best for, but will work OK.
I'm doing drain and refills every 10k on both 06 Toyotas we have with Amsoil until the 30k mark, then every 20k from that point forward. Both rigs are shifting butter smooth.
I'm starting to see some people are now using Amsoil in Hondas in place of the Z1, so I may put it in the daughter's Civic as well.