How to tell hydrocracked oil apart

If the packaging doesn't state that the oil was made using hydrocracking technology, you can only tell by indirect signs (price, viscosity, and so on).

The thing is, engine oil manufacturers, so as not to scare car owners off with complicated, unfamiliar terminology, and also taking advantage of the fact that the American Petroleum Institute recognises hydrocracked oils as synthetic, print something along the lines of "synthetic technology" on their packaging. Some manufacturers don't state the production method of the base at all.

Broadly speaking, the production technology is a trade secret for any manufacturer, so this "secretiveness" on the part of oil makers is justified not only from a marketing and psychology standpoint.

A far more relevant question, it seems to me, is a different one — do you actually need to tell them apart at all? After all, as a consumer, what should interest you isn't the question of "how the oil was made", but the question of "can it be used", right?