What API Service Classification Is Required for Your Engine?

 

The service rating of passenger car and commercial automotive motor oils is classified by the American Petroleum Institute (API). The program certifies that an oil meets certain Original Equipment Manufacturer (OEM) quality and performance standards. The service rating is shown in the API "Service Symbol Donut" on the product label.

 

api

The labels include two important pieces of information to determine if an engine oil is appropriate for use in your vehicle. The first piece of information speaks to viscosity grade. The Society of Automotive Engineers (SAE) defines a numerical system for grading motor oils according to viscosity. The suffixes (0, 5, 10, 15 and 25) followed by the letter W designate the engine oil's "winter" grade.

Look to your owner's manual. It specifies the viscosity grade required for your car's engine. Today, the most common grades are 5W-30 and 10W-30.

 

Watch for the "W"

Whereas the labeling on the bottle of engine oil may suggest the product is a 10W-30, note, if there is no "W" between the 10 and the 30 it may not be a 10W30. As an example, a SAE 10-30 is not the same as an SAE 10W30.

 

API SERVICE CLASSIFICATION FOR PASSENGER CAR ENGINE OIL

api

 

Gasoline Engines
Category Status Service
SM Current For all automotive engines presently in use. Introduced November 30, 2004. SM oils are designed to provide improved oxidation resistance, improved deposit protection, better wear protection, and better low-temperature performance over the life of the oil. Some SM oils may also meet the latest ILSAC specification and/or qualify as Energy Conserving.
SL Current For 2004 and older automotive engines.
SJ Current For 2001 and older automotive engines.
SH Obsolete For 1996 and older engines. Valid when preceded by current C categories.
SG Obsolete For 1993 and older engines.
SF Obsolete For 1988 and older engines.
SE Obsolete CAUTION - Not suitable for use in gasoline-powered automobile engines built after 1979.
SD Obsolete CAUTION - Not suitable for use in gasoline-powered automobile engines built after 1971. Use in more modern engines may cause unsatisfactory performance or equipment harm.
SC Obsolete CAUTION - Not suitable for use in gasoline-powered automobile engines built after 1967. Use in more modern engines may cause unsatisfactory performance or equipment harm.
SB Obsolete CAUTION - Not suitable for use in gasoline-powered automobile engines built after 1963. Use in more modern engines may cause unsatisfactory performance or equipment harm.
SA Obsolete CAUTION - Not suitable for use in gasoline-powered automobile engines built after 1930. Use in more modern engines may cause unsatisfactory performance or equipment harm.