Actually SkyActiv-Drive transmission is still a conventional hydraulic step automatic transmission. The key difference is it minimized slipping torque converter usage to improve fuel economy and provide more of a direct drive feel. it programmed the lock-up clutch inside of torque converter locking whenever possible. In order to maximize lock-up range, NVH performance and clutch reliability were also improved accordingly.
Yep, and here is a visualization.
https://www.youtube.com/watch?v=rqHGnfnQPk4
My question is...how does this affect fluid temps? How does this affect shearing? How does this affect wear and tear of the fluid and the transmission, as well? How critical are the parameters of the fluid?
So far, I have only seen one UOA from a SkyActiv, and it appeared to have, at 67K miles, similar wear and tear as fluid from a 24K mile transmission, per the institution analyzing it.
Would you say that conventional fluid in a conventional transmission is good for 100K miles before transmission failure? If so, extrapolating, that is 268K miles of driving with the SkyActiv without changing it. What if you say "Nah, you can get 150K miles out of a conventional box with regular fluid, then it's prolly gonna die"...well, that's 400K miles from the CX5, at which point, the engine and other things have likely had issue, or more likely still, it was wrecked/you traded it/whatever.
Regardless, NOONE out there has a CX5 with 250K+ miles that I have seen, and noone out there has reported a failure due to fluid, that I have seen. If you or others have seen either, please post, as it would be informative! My point being, the benefits of changing the fluid remain theoretical, as do the detriments of NOT changing the fluid. The only FACTS we have, is that changing t he fluid is dangerous (you or the technician can make an error), and it costs money. These last two, are why everything taken as a whole, I have not, nor will I change it, based on current evidence. I constantly scour this forum and the 'net looking for more on the matter though, honestly, I am curious.