QSA® testing protocol was purposely designed to isolate, identify and measure the specific degradation by-products responsible for the formation of sludge and varnish, there is no other commercial technology like QSA® offered in the marketplace. QSA® does not use traditional oil analysis methods or instruments. Through field research, we developed the Varnish Potential Rating (VPR℠ ), in which severity levels are application specific. Until QSA® was developed, there never was a VPR℠.