mdocod's opinion sounds about right. Two VOAs side-by-side will likely show us a difference in add-pack numbers.
Base Stock differences?...... I dunno. I sspect some Natural Gas base, mainly because the Ultimate in 5w30 is thinner viscosity than the default, vanilla QS Synthetic.
That's the norm with Natural Gas and SOPUS........ gets thinner - shears a little less and lasts longer.
Our Kia 2.0 MPI was NOT fond of Quaker State Euro 5w40 this past summer. I was expecting a quieter engine and instead, it got louder.
I've never had much luck with Quaker State products. My former S-10 with 4.3 used the 5w30 for 4k and the magnetic oil drain plug bolt was loaded with shiny silver shreds. That's the only time it happened and I owned that vehicle for 15 years, before donating it at 155k,to a desperate, needy family down my street.