Here is what Blackstone said: "We test the high temp 210F in our standard analysis, and at that temp, the viscosity is in the 5W/20 range. It's at the top of that range, but still within spec. I had the viscosity tested once more, and the results came back the same.
We do offer a low temp viscosity (LTV), but that is a separate test and an additional cost.
Sorry for any confusion.
Samir Kharbas
Blackstone Laboratories"