The moment its re-blended, the API certification won't apply, unless it was sent for certification again.
IF what you said is true, that XOM re-blends the Malaysia oil, then it DOES NOT MEET API. Why?
API EOLCS | Brand Search Results
Example, EMG MARKETING GODO KAISHA is the one selling Mobil 1 in JAPAN in metal cans, different from USA. And here you see they applied and gotten their API certification for re-packed Mobil 1. I can only guess that it is a different blend as well.
HAhahah! Good catch. This I gotta go find out. The thing with Exxon is it has so many subsidiary companies you'll never know how the whole thing works. But I'm sure a multibillion dollar company can afford to certify and legitimize their products. Besides, why expose themselves for lawsuits?
Eh.. how do you know the acronym XOM?