Apparently this was redesigned to address the shudder issues with the 8L45 and 8L90 but some folks report very good results in the 6A. It seems like the base stock of the Mobil 1 fluid was changed in response to a moisture absorption issue. In some ways this does not surprise me. Water in transmission fluid has been the case of shifting/TCC issues for a long time, and plenty of TSBs have been written. However, I think there may be other additives (vitamins and minerals as VGG would say). For example, the additive that makes the Lubegard product solve TCC shudder issues: is that (or a similar additive) contained within this new M1 fluid? I always thought if this additive cures these issues, why is it not just part of the fluid chemistry?
https://gm-techlink.com/?p=11127
Makes me wonder if it would be good for my 5L50 which originally shipped with Dexron III but now has VI in it. However, it requires the Lubegard additive to stave off the TCC shudder issues. Just makes me wonder if a 100% flush with this new fluid would be the best thing.
Info about the new Dexron LV fluid
Re: Info about the new Dexron LV fluid
Rockauto sells the new fluid for $7.16/qt while 'normal' AC Delco Dex VI is between $5.73 and $6.41/qt depending on what shape bottle you want, so not too much more expensive. I wonder how well it works in 4L60E's? Going from high mileage Dex III to Dex VI is quite an upgrade in an old transmission.
Re: Info about the new Dexron LV fluid
I feel like the oldest transmission it's really meant for would be the 6L series. I don't even know if I'd put it into my 5L50. It does well with Dexron VI and the anti-shudder additive.