Maybe these guys have something new that works? I am always open to a new "Mouse Trap". After all, we did through away the stone tables a while back for something Al Gore supposedly invented called the internet. And being a Curious George I found this as an excerpt from a ZDDP study.
"The results described show that ZDDP reaction films can produce high friction in intermediate speed conditions even when the films formed are quite smooth. Thus reaction film roughness is not the main origin of the friction-enhancing effect. Instead the effect appears to be due to reduced lubricant entrainment when a ZDDP reaction film is present on one of the rubbing surfaces.
CONCLUSION:
ZDDP reaction films formed in rubbing contacts are known to produce enhanced friction in mixed lubrication conditions. In previous work this has been ascribed to a roughening of the surfaces due to the reaction film. However the current work shows that this is not the case; instead the ZDDP reaction film appears to inhibit lubricant entrainment into the contact, thereby leading to a reduced EHD film thickness compared to ZDDP-free lubricants."
So my thought is if these guys have found a way to supply protection with out adding friction, just maybe it is worth a look. We are all looking for help here. I am not looking for any kind of an argument here, we just need to keep an open mind. Their web site is very interesting and brings up some good points to consider.
My point is that an additive is SO "under radar" that its highly unlikely to be the target for removal from the market in its additive form. Taking out of the oil solves 99.999% of the problem due to the incredibly small minority of people that will actually put a zinc ADDITIVE in the crankcase. Tetraethyl Lead was removed (I think?--maybe you can still buy it as an additive?) but that was a pretty visable issue (Lead is poison that everyone equates to ruining our children's lives), I don't think the 'zinc kills catalytic converters over time and therefor leads to more pollution from high mileage cars' is in the same league in terms a problem that needs to be addressed.