To be honest I wouldn't know why any formulator or manufacturer would tell you. I would ask in response, what does it matter? I'd ask you why that would make any difference. The operative word in any question would be "why".
I would ask you what specifications your engine requires, and then tell you which products meet those required specifications. I think that's pretty much what ExxonMobil does.
Conversely those formulators that constantly harp on base stock are often the weakest on specs.
I would ask you what specifications your engine requires, and then tell you which products meet those required specifications. I think that's pretty much what ExxonMobil does.
Conversely those formulators that constantly harp on base stock are often the weakest on specs.