Herein, Can you mix Full Synthetic with semi synthetic oil?
There is no danger mixing synthetic and conventional motor oil; however, conventional oil will detract from the superior performance of synthetic oil and reduce its benefits. The detailed answer: With synthetic lubricants continuing to grow in popularity, the question of whether synthetics and conventional oils can be safely mixed often arises.
What happens if you mix regular and synthetic oil?
No you cannot mix synthetic and regular oil. The synthetic creates a barrier on all moving parts which the conventional oil cannot pass through. A 50/50 mix would cause your engine to only utlize half of the oil which is bad no matter what the vehicle.
What are the disadvantages of synthetic oil?
For many, the biggest disadvantage is the cost. A quart of fully synthetic oil may cost upwards of $6.00 to $10.00. Also, some pundits will argue that synthetic oil is not good for some engines. An older car may not be able to handle some forms of synthetic oil and it may cause the engine to leak oil.
Can you replace synthetic oil with regular?
No matter whether the oil in the engine is synthetic or regular oil, you can add either oil as needed between oil changes. Adding regular oil before an oil change is one way to reduce the cost of oil used in a vehicle.
Can you mix different brands of oil?
It is okay to mix different brands of motor oil as long as the oils have the same grade and clasification. They must match grade i. e. "10w30", and they must both have the same "SM", "SJ", "SL" classification for gasoline engines. Diesel engines use "CJ", "CL", or "CM" classifications.