Synthetic or regular oil? I need to change the engine oil

Hello,

Well, the simple answer is yes. You can mix conventional and synthetic oil.
However conventional oil will reduce the benefits of the synthetic oil typical superior performance like longer life span and improved lubrications.

Here is a helpful guide of how to change the oil:

https://www.2carpros.com/articles/how-to-change-engine-oil-and-filter

Hope this answers your question.
Thank you.