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Q: I had an oil change and Castrol GTX was used, which I assume is not a synthetic oil. Will that harm my engine.

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will regular engine oil used for an oil change harm the Subaru 2013 legacy 2.5 which has before this always had synthetic oil

My car has 25000 miles.
My car has an automatic transmission.

A: Synthetic vs conventional oil is one of the...

Synthetic vs conventional oil is one of the most debated myths surrounding the topic of oil changes. This will not hurt your engine when switching from synthetic to conventional or vice versa. In fact, Synthetic blend oils are actually a mix of conventional oils and synthetic oils. It is recommended that you use the same oil to top off when needed, giving you the best protection from the oil you have chosen to use in your vehicle. Many people often wonder about the benefits of using synthetic oils.

Many synthetic oils are made up of a base oil of approximately 80%, with other additives making up the remaining 20%. The main difference between the molecules in synthetically engineered oils are the uniformity of the molecules, while the molecules found in most conventional oils differ in shape, size and impurity. The type of oil that should be used for a specific application depends largely on the driver’s driving habits, the environment in which the car is driven, the mileage on the car’s engine and the limits that the engine may be pushed to. I would recommend having an expert from YourMechanic come to your home to perform an oil change service on your car to determine the best option for your vehicle in the future.

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