To determine what oil you need for your car, you should consult your vehicle owners manual. The manual will provide the necessary details on the proper oil viscosity grade (e.g. SAE 0W-20, SAE 5W-20, SAE 5W-30 or other) as well as the performance specification. The recommended oil type may vary depending on factors such as the engine type, engine size or displacement, use of turbochargers or direct fuel injection, and incorporation of emission control components such as catalysts and particulate filters. If your car has a turbocharger or supercharger, or if you have a high-performance model, the required type of oil is often semi-synthetic or fully synthetic. Some oil companies offer online databases to search for the right oil for your vehicle’s make and model. If you are still unsure, you can consult a professional mechanic for help.