I just took a peek through the XOM SDS vault (be sure to put a dash inside the oil grade or you will be frustrated!) and was surprised by what I found. Googling "1-DECENE, HOMOPOLYMER HYDROGENATED" has assured me that this is a type of PAO and these are the levels that XOM reports for three oils I am interested in. M1 5W30 - 20 to 30% M1 0W30 AFE - 10 to 20% M1 5W30 AP - 5 to 10% I know that PAO level on its own doesn't tell us much about the overall quality of the oil in use...but I was surprised that 0W30 didn't use more to help with low temp pumpability/cranking performance and also surprised that AP was the lowest concentration of the bunch. Apologies if this has already been discussed... BTW, these were for US products.