Antifreeze for Hyundai and Kia
This is the strongest single entry on the whole data sheet. For other brands Valvoline states “meets or exceeds”, but for Hyundai and Kia MS591-08 it states outright that this is an approved formulation. That is a different and higher class of claim. And the first two names on the front of the green bottle are Hyundai and Kia.
Hyundai and Kia's factory MS591-08 coolant is green, and both names are printed on the front of the green bottle, so here we recommend the green. If your tank holds a clearly blue fluid, take Zerex Asian Blue.
Photographs come from the manufacturer's official materials.
The difference between “meets” and “approved”
“Meets or exceeds” means the manufacturer has tested the product against that standard's requirements and declares conformity on the basis of the results. That is a fully legitimate and industry-standard claim.
“Approved” is a step above, because it means the formulation has been through a process controlled by the owner of the specification itself. On the Zerex Asian Green sheet, that status is stated for Hyundai and Kia MS591-08.
Sonata, Ioniq, Niro and Optima hybrids
Hyundai and Kia hybrids also have a separate cooling circuit for the power electronics, and the same logic applies, because narrow passages do not forgive deposits.
Zerex Asian Green measures under 10 ppm silicon where the JIS limit allows 250 ppm, contains no borates, and carries a phosphate package that works against deposits and scale.
Still verify the specification listed for each circuit in the manual.