RP data sheets used to show that they had a couple of grades (e.g. the 0W40) that were definitely at the top end, and the products in the adjacent columns were pretty ho-hum WRT CCS, MRV and the like.
Can't show you that, as RP censor these data sheets that I used to criticise...can't get them, can't link them.
Happy to be proved wrong by the fanbois however, as I've offered before...hook us up with the data sheet, as opposed to the menu that links to the data sheet.