Not all motor oils are the same, but you may not know that at the outset. Learn how synthetic engine oil compares vs conventional and semi-synthetic blends.
Motor Oils are formulated and marketed as conventional, full synthetic, part synthetic and semi synthetic. What is the difference between synthetic and semi synthetic or semi synthetic and conventional? The difference lies in the type of base oils that are used in the formulation and this is what defines these motor oil categories.
The base oil used in a conventional motor oil is 100% mineral oil which is obtained through the refining of crude oil. Here the crude oil is distilled and cleaned up to produce a high-quality base oil. This is done without substantial molecular changes being made to the hydrocarbons in the base oil during the process.
A synthetic base oil is derived though the creation of new base oil components (synthesis) to produce a stronger performing base fluid.
The use of synthetic base oil can substantially improve the performance of the motor oil. Synthetic base oils
The more synthetic base oil contained in a motor oil in general the better the performance. In turn, a full synthetic motor oil formulated with a robust additive system will always be better than synthetic blends. That said a properly formulated semi-synthetic can offer performance benefits over a conventional motor oil.
Adding synthetic base oil to motor can produce a stronger motor oil due to the benefit of synthetics. Depending upon the amount of synthetic in the base oil composition the semi-synthetic motor oil can be more resistant to the various factors that can degrade a motor oil. Castrol incorporates a material amount of synthetic in our part synthetic formulations to help improve oil burn off performance as well as low temperature flow. That said a robust additive system is also critical to the overall performance of the motor oil. Thus, one must consider both in judging performance. While the incorporation of synthetic can produce stronger motor oils Castrol always recommends that one follow the vehicle manufacturers recommendation for oil service and engine oil drain intervals.