If it says it's a "synthetic blend" then it has more Grp. I or II oil than a "full synthetic". Which still has some mineral oil, in order to solubilize some additives if nothing else.
However, the "Group" classification definitions are on the basis of viscosity index, high VI being better. In order to have a given VI, a "synthetic blend" will contain more VII (viscosity index improver, a long chain polymer) than a "full synthetic". This is what people complain about shearing, and when it does viscosity at 100 C. drops. Not a really big problem, xW40s typically shear to the high end of the xW30 range, but people don't like the idea of it. Some engines shear oil much more than others, especially Powerstrokes due to the HPOP (high pressure oil pump for unit injectors).
FWIW, in your nice little high performance car I'd use an ACEA A3/B4 oil. But the 5W40 syn blend you're looking at has the critical characteristic: HTHS>3.5 cP @ 150 C. Because it's an HDEO.
Charlie