Synthetics and semi-synthetics give improved performance at high temperatures and support extended standard drain intervals. They are the preferred choice for high perfomance cars or for drivers who value long life/durability.
- Your vehicle handbook will specify the grade/type of oil to be used based on durability/extreme environment testing by the manufacturer.
- If synthetic oils are recommended then that is what you should use.
- Mixing mineral and synthetics is not recommended, nor is switching to synthetic oils unless the vehicle handbook specifies that you may do so.
If the manufacturer has confirmed that synthetic oil is suitable for your vehicle and you intend to switch then you must make sure that the engine is drained fully of mineral oil first.