Where did you find out its Group IV? IIRC, its Group III for their street oils and is the reason why its hated so much, Group IV for their race oils eg RP 21.
Then again they might have changed their formulation in the last few years, or the speculation was wrong. Hmmm. I'd rather spend the same $$ on Motul 300V or Redline which are proven performers without the questionable hype.