How many types of fully synthetic engine oil are there?

[MacRiley]

Fully synthetic engine oil is divided into two types: fully synthetic oil and semi-synthetic oil. Fully synthetic oil is the highest grade. Increased fuel consumption: When adding engine oil, the oil level should be between the upper and lower limits on the dipstick. If too much oil is added, the engine temperature will rise, causing the oil to expand in volume. This increases the pressure in the oil chamber, raises operating resistance, reduces vehicle power, and leads to increased fuel consumption. Overfilling engine oil: If too much oil is added, the crankcase vent pipe may leak oil. The increased pressure in the crankcase can loosen the oil seals due to oil pressure, resulting in oil leaks. Heat dissipation: Overfilling engine oil can affect the engine's heat dissipation.