My guess is that it is now a group 3+/PAO/Ester blend.
Sadly, on most of the 300V Ester Core weights, the VIs and TBNs have gone way down.
2000 Z28 1SC 6 speed 180K miles
4L Motul 300V 0W-40, 2L Motul 300V 0W-20
M1-206 oil filter
Motul Gear 300 75W-90
Red Line D4/MTL in the T56