Service Rating - This two letter classification identifies the vehicle fuel type and quality level of the motor oil. The first letter indicates the vehicle fuel type that the oil is designed for. The second letter designates the quality level of the motor oil. An SJ oil can be used in any engine requiring an SB, SG, SH, etc. Viscosity Grade - Viscosity is a measure of an oil's thickness, or resistance to flow.
Lower numbers indicate thinner oil and higher numbers indicate thicker oil.
There are two types of motor oils, single grade and multi-grade. Multigrade oil such as a 10W-30, are designed to have the viscosity of an SAE 10W oil at cold temperatures combined with the viscosity of an SAE 30 oil at engine operating temperatures. Energy Conserving Oils displaying this phase are formulated with friction modifiers to improve fuel economy in an industry standard test.