Looking at the spec sheets, then it’s the ‘6+’ you would want. The Volvo AW1 spec oil is extremely high quality (hence the price), with low viscosity (~26) but very high shear index (~170). I don’t know for sure who makes it, but I suspect as its made in Canada, that it’s PetroCanada.
You have loads of options for AW-1/jws3324 spec. I’ve been using this:
https://www.smithandallan.com/produc...mission-fluid/
My box needed quite a few dumps to clean up, and is essentially still a work in progress hence I got the 20L drum.