What is the identification for fully synthetic engine oil?

[LaSadie]

Fully synthetic engine oil does not have a specific identification mark, but the bottle will be clearly labeled with the words 'fully synthetic'. The functions of fully synthetic engine oil are: 1. Between the piston and cylinder of the engine, as well as between the main shaft and bearing bush, there exists rapid relative sliding. The engine oil forms a sufficiently thick oil film between the two sliding surfaces to separate the relatively sliding parts and reduce wear; 2. It carries heat back to the oil tank and then dissipates it into the air, assisting the radiator in cooling the engine; 3. It circulates carbon deposits, sludge, and worn metal particles from engine components back to the oil tank, flushing away dirt generated on the working surfaces of the parts through the flow of the lubricating oil; 4. It provides shock absorption and cushioning when the pressure at the engine cylinder port rises sharply, suddenly increasing the load on the piston, piston chips, connecting rod, and crankshaft bearings. The load is transmitted through the bearing lubrication to cushion the impact load.