The engine dynamometer testing of crankcase lubricants that is required to demonstrate API CC/SF quality fails to provide significant discrimination when applied to oils formulated to far exceed these minimum performance targets. Lubricants with increased levels of dispersancy and detergency (“Super Premium World-class Oils”) have been compared in these tests and also in severe field tests to oils of standard quality API SF or SF/CC quality. All of the standard quality lubricants used as reference oils in this work have given satisfactory field performance in normal service. The severe service conditions in this report are believed to be similar to those encountered by a small but significant proportion of vehicles in the world. The Super Premium products have outperformed the reference oils under both low and high temperature conditions in severe field tests run in North America and Europe. The superior performance was evident in used oil condition, in engine sludge deposit control and in wear protection.