Originally Posted By: kschachn
Originally Posted By: TiredTrucker
You mean like Amsoil's straight 30w that meets a 10w30 spec but they still list it as a straight 30w? There is no requirement that a 10w30 oil be "labeled' a 5w30 if it meets the spec. It is only "required" by Federal law to meet the spec that it is labeled for. The law requires a product to meet the standard it claims. There is no law that says it cannot be better than what is claimed.
You're mixing up "laws" and requirements. API J300 requires that the oil be labeled for the lowest "W" rating it achieves.
Yep, J300 allows only lubricants that have no viscosity modifiers to be listed either as a "straight weight", OR as a multigrade, OR as both...as per Amsoil.
However, IF the oil has Viscosity Index Improvers, it must be labelled to the lowest rating that it achieves.
I'm a bit interested in where Tired Trucker's "Federal Spec" document is, and lives, and would really like to see a PDF of same...