i'm by no means an expert on hsd but technically, isn't the torque ratio fixed at about 72% to sun gear 38% to ring gear? it's the power that is variable right?

also, i don't understand how you're defining "variable ratio" and "transmission". some would argue that psd isn't really even a transmission.

one challenge i see in trying to categorize psd as cvt is that at higher road speeds (lets say greater than 80mph), the motor/generator attached to the sun gear (mg2?) is going to consume more and more power as speed increases thus requiring more power from the ice at maybe 30% inefficiency. that means the ice is going to have to work harder to provide the power. this quirk gives me pause when considering psd a true cvt. obviously a belt and pulley cvt doesn't have this problem.

so at lower speeds, psd appears to act like a traditional cvt but at higher highway speeds it starts acting less and less like one. i would imagine there is a speed limit where mpg drops precipitously b/c the ice is working so hard to overcome the inefficiencies of the mechanical->electrical->chemical->electrical->mechanical energy conversions.

like i said, i'm not fully an expert on psd but this latter point merits discussion i would think.