I would never put the word "best" in a sentence with Maxlife.
I have an '08 G35X and I might use non-Nissan ATF fluid in it. I bought it from my sister with 95k miles and in that time, she had the ATF drained and refilled twice by dealers, so it presumably got Nissan Matic J or S. It's at 175k miles now and I've done multiple drain and refills and can't notice anything other than gear changes definitely feel "nicer" after the changes.Used Maxlife in my 2006 Nissan Sentra transmission, and it didn't shift right afterwards. When cold, the trans had a delayed upshift, hanging in lower gears way too long. There were flared shifts, mushy slow shifts, all depending on load. It wasn't bad enough for me to swap it out, but I'd never use that stuff again.
The OEM engineers spend tons of time fine tuning the TCU. Tiny differences in shift logic programming can make noticeable changes. And needless to say all this tuning is done with the OEM fluid. Maybe some transmissions can digest generic fluid, but some won't.
Nissan Matic-D for my old Sentra. Dextron VI is the claimed equivalence, but it's notI have an '08 G35X and I might use non-Nissan ATF fluid in it. I bought it from my sister with 95k miles and in that time, she had the ATF drained and refilled twice by dealers, so it presumably got Nissan Matic J or S. It's at 175k miles now and I've done multiple drain and refills and can't notice anything other than gear changes definitely feel "nicer" after the changes.
There's rather loose evidence that Matic J is simply Castrol Transmax J (and labeled Import Multi Vehicle in the US) and coincidentally, when Nissan switched to Matic S, Castrol released their full synthetic ATF. In the case of my transmission, JATCO supplies the same one to Subaru and they don't "require" Matic J or S.