Found this article.This study shows that artificially polymer thickened
oil (Multi-Grade)
will tend to have a higher temporary viscosity loss (shear) under load
than an
oil who's base is the same viscosity (straight weight
oil). In
otherwords, multi-grades tend to fail, break down, loose viscosity when
it is needed most... under load, whereas a straight weight oil will not. This sounds like its sayin that multi grade is inferior to strait wght oil ?
http://resources.metapress.com/pdf-p...0&size=largest