Originally Posted by Mo_The_Car_Guy
Thank you for the reply, can I ask you to tell me more about the specs of the new factory cvt fluid? And if I'm not bothering can you explain what do you mean by "wear-in"?
I haven't really been into the cvt fluid. The best link I've found is here.
I've also seen where fluid for cvt metal belts is different from fluid for cvt chains, like in the new Subaru cvt.
As far as "wear in" If you have ever looked at differential or other gears that have been sliding on each other for awhile there is an area (hopefully in the middle of the face) that is shiny. That's what I'm referring to as "wear in".
When a motor is slightly worn any restrictive areas are polished off as above, and tend to perform better. Engine parts are built to tolerances, and even if within the tolerance of individual parts, one part at one extreme and the facing part at the other extreme can cause extra friction. "Break in" is to start to wear those parts while they are so far off extreme use can cause a problem, rather than just be a friction point.
One spot on an engine is no big deal, but there are lots of parts in engines... Changing to a type IV synthetic before the engine surfaces are optimized to each other could extend the time before those surfaces mate. That's the way I understand it.