Generally, you should not mix synthetic oil with regular oil. While it might seem harmless, mixing these two types of oils can lead to several issues:
- Reduced performance: Synthetic oil is formulated for higher performance and longer life than conventional oil. Mixing it with regular oil dilutes its benefits, reducing its effectiveness.
- Potential for sludge: The different chemical compositions of synthetic and regular oil can cause them to react, creating sludge that can clog engine parts and reduce efficiency.
- Warranty issues: Mixing oils can void your engine warranty, as manufacturers generally require specific oil types for optimal performance and protection.
If you have already mixed synthetic and regular oil, it's best to drain the mixture and refill with the recommended oil type for your vehicle.
Remember to always consult your owner's manual for the recommended oil type and change intervals for your specific vehicle.