A couple....
"The combination of local high temperatures, increased surface energy, and any catalysis or activation process that may take place, makes the action of EP additives more specific, taking place preferentially at the wear points where it is most needed."
That's one of those things that Amsoil would say... It sounds absolutely wonderful. An additive that will seek out wear and eliminate it on an as needed basis. It's misleadingat best. Accurate for sure, but misleading as far as the actual function. You've got to have an EP application before you can make use of an EP addative.
The first thing you need is the correct gear design, then you need enough torque and speed..... Most things that get GL5 can't "activate" the additives, which is a good thing, but they are also not adversely affected by the additive while it's waiting for it's big chance to shine which probably will never occur.
"EP additives are, in fact, selected to obtain the best balance between corrosiveness and protection for the wide range of systems in which they are used."
Indeed they are, but again it's a bit misleading. This one doesn't sound line an Amsoil quote, but it does sound easily misinterperited. Best "balance" means that they can't eliminate the issue of corrosiveness, not that they've fixed it. And the "systems in which they are used" part means more "systems in which they are called for" than it does "systems into which you pour it".
Remember, these oils are made to standards that did not exist when the transmission was made, and transmissions constructed with the techniques and materials that these transmissions are constructed of are virtually obsolete, therefore the newest, latest and greatest oil products out there don't need to consider it.
Also consider this-
GL-1 is NOT obsolete.
GL-2 IS obsolete, replaced by GL-3
GL-3 IS obsolete, replaced by GL-4
GL-4 is NOT obsolete.
GL-5 is NOT obsolete, of course it's a new specification (relatively speaking) that did not superceed anything.
If GL-4 were the same thing as GL-1 only better, wouldn't it follow that GL-1 would be obsolete?
If GL-5 with MT-1 were truely backward compatible, would it not follow that it would make GL-1 AND GL-4 obsolete?
GL-2 through GL-4 are not free of the corrosion issue at all. They have the addatives that are at issue with the deuce transmission, just in somewhat reduced quantities when compared to GL-5.