MYTH: Switching motor oil brands is harmful to my engine.
No. Switching brands is not harmful to your engine as long as you choose an oil marked with the API donut of the same level, e.g., API SN. Motor oil manufacturers must meet minimum industry standards for performance and compatibility of the API mark. However, make sure you follow the recommendations provided in your owner's manual for viscosity and API category. You may give up enhanced performance if you switch from synthetic or high mileage to conventional oil.