Chrysler 2005 PT Cruiser - Manual (Page 272)

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 tempera-
ture 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 certi-
fication mark and the correct SAE viscosity grade num-
ber 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 recom-
mended SAE viscosity grade. Follow the maintenance
schedule that describes your driving type.
272 MAINTAINING YOUR VEHICLE