At this site, the following claims are made about synthetic base oils:
"synthetic base fluids provide the following advantages:
High-temperature stability
Improved wear protection
Reduced deposit formation
Improved cold-temperature flow properties
Extended service life
Waste minimization through reduced consumption
Energy conservation
Low volatility
Improved biodegradability
Viscosity control over a wide range of temperatures"
Isn't the cleansing of the engine (being mentioned on this board) after adding a synthetic motor oil really due primarily to the dispersant/detergent additive systems found in these oils rather than the base oil in use itself?