Anyone?
Doesn't the A5 spec have to do with extended drains compared to the A1 spec and isn't the XL line supposed to be for extended drains? (Though maybe not as extended as Amsoil's PAO oils.) So where does the XL 5w30 fall short? and does it matter? and even if not, why doesn't Amsoil try to meet the spec just to be able to put it on the bottle for comparison to, dare I say it, Mobil 1 Extended Performance 5w30 which does.