SYNTHETIC VERSUS PETROLEUM
Any oil properly rated for use in a high-performance turbocharged engine is a
remarkable lubricant regardless of the base oil used in the finished oil. In this
article, I will compare synthetic engine oil to petroleum engine oil, draw
some conclusions, and make some recommendations. To start, we should
compare several performance criteria for synthetic versus petroleum oils.
Thermal stability: How well does the oil hold viscosity as temperature
increases? This is reflected in the Viscosity Index (VI) rating illustrated in
chart one. Oils that maintain rated viscosity instead of thinning out at higher
temperatures are better oils. Thin oil will reduce film strength and result in
higher wear rates of critical engine parts.