G12 plus is G012 A8FA4
It seems that one question here is whether G12 plus is different than VW/Audi part number G012 A8FA4, and the other question is whether it can be added to "purple coolant". Also, if G12 plus is substantially different than G12 plus plus. I am not sure where the plus comes from, but I think this refers to the new G12 that supersedes G012 A8FA4. Maybe someone can clarify that. To answer the first question (or just add more controversy!):
ECS tuning appears to call G012 A8FA4 by the name G12 plus. They do state it is no longer available, but...Here is a link to the webpage:
http://www.ecstuning.com/Search/G012a8fa4/ES4330/
where is states two things. First:
"OEM VW / Audi replacement fluid for all vehicles that came with purple antifreeze"
NOTE: It is definitely pink.
and then, a description:
G12 Plus is an antifreeze for passenger cars and trucks meeting the quality requirements of the automotive manufacturers especially suitable for alloy engines. It protects excellently against corrosion and cavitation does not foam prevents lime formation and is neutral to different types of metals rubber parts and sealing materials which are used in the engine construction. It is produced under stringent quality controls and has proved excellent operating performance in daily use. G12 Plus free of nitrite amine and phosphate.
As far as I am concerned, any minor differences that might or might not exist between the pink stuff in my coolant reservoir and G012 A8FA4 will not reduce the performance of the coolant that is in there. It is pink as well.
And, information on this website say OK to mix purple and pink or red coolant
http://blauparts.com/vw/vw_fluid/vw_coolant_engine_fluid.shtml#bluevwcoolant
An important quote from the site
The purple and above pink Vw coolant are interchangeable and can be mixed.
And another (similar statements are made FOUR times- once in descriptions for red/pink and purple coolant descriptions.
This pink and the below purple Vw coolant are interchangeable and can be mixed.
They also state NOT to mix blue or green coolants together, or mix them with pink or purple coolant. Oddly, there is a statement that there is ethylene glycol in green coolant (well, yeah!), and if you mix pink or purple with green, you must flush (!).
But my bottle of G012 A8FA4 clearly states that is contains ethylene glycol (and it is pink?!). Just weird, isn't it?
I would guess that a mixture of the chemicals in these was probably tested at some point during development.
The current formulation is probably lacking/gaining one or two less expensive ingredients, or less of a more expensive ingredient that was deemed unnecessary (cost cutting-profit driven change).
I got a gallon of G012 A8FA4 with my old 2003 Jetta years ago (was in the trunk). It is still sealed. I am topping off the reservoir this weekend with it, because the level in the reservoir has dropped just enough to cause conductance between the prongs to dip below set point periodically, and the warning sound and light are triggered.
This will fix it. And I would be very, very surprised if there were any unforeseen consequences in my lifetime. I will flush and refill in another year anyway.
What the heck. As far as adding pink to purple goes... I would do that as well and Blauparts doesn't warn against this. Who knows, it might actually work better! But it is unlikely to cause precipitation, lime scaling, corrosion, degradation of seals, etc... and it probably would result in a solution that resists cavitation and doesn't foam. Think about it... these formulations are designed specifically to be NOT reactive, and NOT to dissolve sealant. They are water soluble and not reactive. They will mix and not react with each other, not dissolve seals, not corrode, not cavitate, and not foam. If the coolant in my reservoir was purple, I would add it anyway.
The real question is... Does anyone here have any credible evidence that mixing purple and pink coolant has resulted in damage to their cooling system?
Based on Blauparts notation that it's OK to mix purple and pink... I think not.