The short answer of this is …… Google them
However ACEA is international company like API who defines the oil ratings. They have different standards for different oils like A1, A2, A3….. B1, B2, B3…. And for Diesel engines C1, C2, C3,.. etc.
Ilsac, same answer as above.
Ai is some sort of additive which they are using for “Marketing & sales purposes”.
Like LM introduced & market MoS2
Kixx introduced & market PAO
Etc.
Dexos is I guess “Dexron”. Again its related to oil performance standards, bahaviours at different temperatures, and OEM’s recommendations. Dexron-I, II, III, Volvo VDS, Renault, MAN, Cummins, etc.
VHVI Is Very High Viscosity Index. And ZIC is purely & purely using it for marketing.
For example if an oil of xW-40 oil should have min. 90cst at 40 degree C. then ZIC oil will have 115cst, Caltex will have 110, shell may be 118, total maybe at 117.
So technically all of them are above 90 which is min. requirement. Hence ZIC is smart enough to use this term as marketing terminology.