I think the spec sheet (see link on page 1 of this thread) has a bit of marketing fuzziness going on. Eg, the superduty column has chk marks by many specs, then gives specific viscosities for other specs. So it would appear that a chk mark would mean that all visc. grades meet the spec - but there's a chk mark in the A3/B3 column - and there are only a few xxw30s that meet A3 HS/HT requirements (I can only think of GC) and I think it's essentially impossible for a xxW20 to meet A3. Then there's the comment at the bottom about visc. vs. specs (ie, a loophole to all that's said in the chart, and then the chart itselt is (as I just described) fuzzy in its own right).
So this means that perhaps only their 10w40 line meets A3/B3 - which to some degree brings the product line back down to earth.