G12 or G13 coolant?

My 2013 R manual says to use G13 coolant, the overfill reservoir is marked G12. (engine code CRZ) Has anyone else run across this? what is the VAG official line on this?

thanks in advance.

G13 is the new G12. It can be mixed, but you're better off not. I read there's a loss of corrosion protection if you mix the 2.

You can intermix the two freely per VW/Audi. You can't buy G12++ any more regardless, which was the last G12. Original G12 was crap for VW's and Audis, which Audi quietly buried by 2007 or 2008. VW and Audi often referred to it all sort of generically as G12, even though the formula changed meaningfully. But honestly who ever bought the 20 million or so coolant reservoirs for VW and Audi corporate never seemed to bother to get the correct labeling on the reservoirs. Chemically original G12 did not have silicates, which are there to prevent internal erosion of cooling passages. Silicates allow the metal to self heal. They found internal erosion in passages in VR6's that apparently affected its heavyweight cousin the W12 too. So, back to silicates with G12++. Presumably Mk6 R's came with G12++, though 2013's could have had G13 fill given the cut over dates for that in production.

But G13 is enviro eyewash crap frankly, literally brought to us by VW and Euro carbon bean counters where there is mandatory regulation. What it is mix wise is G12++ cut with 25% glycerin (aka soap essentially) to reduce the use of petroleum ingredients. Personally, if I wanted my coolant cut with soap, I would add it myself. But, all academic since AFAIK there no longer is any available G12++. Pentosin had it under the Pentofrost ++ brand, but gone from market as of 1-2 years ago. VW/Audi no longer sold it as of circa 2014. Pentosin G13 product that supersedes its ++ flavor is now called E.