Quicksilver 25/40 oil

[drivingacar]

I see that the Quicksilver 25/40 oil states it is a unique oil without VI improvers to break down. How would this type oil be formulated to accomplish that?
I read this on the bottle label but I could not find any information about it on the web

 

[JonS]

I have a post about this in the boat, lawnmower section. It looks like good oil for my boat, But the dealers and the factory (PCM, Ford) tells me i stillshould use a straight weight 30 or 40. They did not like the Quicksilver brand.