2005 Chrysler PT Cruiser Owner's Manual - Page 272

272 MAINTAINING YOUR VEHICLE Engine Oil Selection For best performance and maximum protection under all types of operating conditions, the manufacturer only recommends engine oils that are API certified and meet the requirements of DaimlerChrysler Material Standard MS-6395. American Petroleum Institute (API) Engine Oil Identification Symbol This symbol means that the oil has been certified by the American Petroleum Institute (API). The manufacturer only recommends API Certified engine oils. Engine Oil Viscosity (SAE Grade) SAE 5W-30 engine oil is recommended for all operating temperatures. This engine oil improves low temperature starting and vehicle fuel economy. Refer to your engine oil filler cap for the recommended engine oil viscosity for your vehicle. For information on engine oil filler cap location, see the Engine Compartment illustration in this section. Lubricants which do not have both, the engine oil certification mark and the correct SAE viscosity grade number should not be used. Synthetic Engine Oils There are a number of engine oils being promoted as either synthetic or semi-synthetic. If you chose to use such a product, use only those oils that are American Petroleum Institute (API) Certified and have the recommended SAE viscosity grade. Follow the maintenance schedule that describes your driving type.