MOTOR OIL GUIDE

part 1

The American Petroleum Institute (API) has classified and identified oil according to its use. The API service recommendations are listed on the oil can and all car manufacturers use API letters to indicate recommended oils. Almost all oils meet or exceed the highest service rating (SJ), but viscosity should be selected to match the highest anticipated temperature before the next oil change. S =Gasoline C =Diesel

API Symbol Use & Definition

SA (obsolete) (Formerly for utility gasoline and diesel engine service) Service typical of older engines operated under such mild conditions that the protection afforded by compounded oils is not required. This category has no performance requirements and oils in this category should not be used in any engine unless specifically recommended by the equipment manufacturer.

SB (obsolete)(Minimum Duty Gasoline Engine Service) Service typical of older gasoline engines operated under such mild conditions that only minimum protection afforded by compounding is desired. Oils designed for this service have been used since the 1930's and provide only anti-scuff capability and resistance to oil oxidation and bearing corrosion. They should not be used In any engine unless specifically recommended by the equipment manufacturer.

SC (obsolete)(1964 Gasoline Engine Warranty Service) Service typical of gasoline engines in 1964 through 1967 models of passenger cars and trucks operating under engine manufacturers' warranties in effect during those model years. Oils designed for this service provide control of high and low temperature deposits, wear, rust, and corrosion in gasoline engines.

SD (obsolete)(1968 Gasoline Engine Warranty Maintenance Service) Service typical of gasoline engines in 1968 through 1970 models of passenger cars and some trucks operating under engine manufacturers' warranties in effect during those model years. Also may apply to certain 1971 and/or later models as specified (or recommended) in the owners' manuals. Oils designed for this service provide more protection against high- and low-temperature engine deposits, wear, rust and corrosion in gasoline engines than oils which are satisfactory for API Engine Service Category SC and may be used when API Engine Service Category SC is recommended.

SE (obsolete)(1972 Gasoline Engine Warranty Maintenance Service) Service typical of gasoline engines in passenger cars and some trucks beginning with 1972 and certain 1971 models operating under engine manufacturers' warranties. Oils designed for this service provide more protection against oil oxidation, high-temperature engine deposits, rust and corrosion in gasoline engines than oils which are satisfactory for API Engine Service Categories SD or SC and may be used when either of these categories is recommended.

SF (obsolete)(1980 Gasoline Engine Warranty Maintenance Service) Service typical of gasoline engines in passenger cars and some trucks beginning with the 1980 model operating under engine manufacturers' recommended maintenance procedures. Oils developed for this service provide increased oxidation stability and improved anti-wear performance relative to oils which meet the minimum requirements for API Service Category SE. These oils also provide protection against engine deposits, rust and corrosion. Oils meeting API Service Category SF may be used where API Service Categories SE, SD or SC are recommended.

API Symbol	Use & Definition
SA (obsolete) (Formerly for utility gasoline and diesel engine service)	Service typical of older engines operated under such mild conditions that the protection afforded by compounded oils is not required. This category has no performance requirements and oils in this category should not be used in any engine unless specifically recommended by the equipment manufacturer.
SB (obsolete)(Minimum Duty Gasoline Engine Service)	Service typical of older gasoline engines operated under such mild conditions that only minimum protection afforded by compounding is desired. Oils designed for this service have been used since the 1930's and provide only anti-scuff capability and resistance to oil oxidation and bearing corrosion. They should not be used In any engine unless specifically recommended by the equipment manufacturer.
SC (obsolete)(1964 Gasoline Engine Warranty Service)	Service typical of gasoline engines in 1964 through 1967 models of passenger cars and trucks operating under engine manufacturers' warranties in effect during those model years. Oils designed for this service provide control of high and low temperature deposits, wear, rust, and corrosion in gasoline engines.
SD (obsolete)(1968 Gasoline Engine Warranty Maintenance Service)	Service typical of gasoline engines in 1968 through 1970 models of passenger cars and some trucks operating under engine manufacturers' warranties in effect during those model years. Also may apply to certain 1971 and/or later models as specified (or recommended) in the owners' manuals. Oils designed for this service provide more protection against high- and low-temperature engine deposits, wear, rust and corrosion in gasoline engines than oils which are satisfactory for API Engine Service Category SC and may be used when API Engine Service Category SC is recommended.
SE (obsolete)(1972 Gasoline Engine Warranty Maintenance Service)	Service typical of gasoline engines in passenger cars and some trucks beginning with 1972 and certain 1971 models operating under engine manufacturers' warranties. Oils designed for this service provide more protection against oil oxidation, high-temperature engine deposits, rust and corrosion in gasoline engines than oils which are satisfactory for API Engine Service Categories SD or SC and may be used when either of these categories is recommended.
SF (obsolete)(1980 Gasoline Engine Warranty Maintenance Service)	Service typical of gasoline engines in passenger cars and some trucks beginning with the 1980 model operating under engine manufacturers' recommended maintenance procedures. Oils developed for this service provide increased oxidation stability and improved anti-wear performance relative to oils which meet the minimum requirements for API Service Category SE. These oils also provide protection against engine deposits, rust and corrosion. Oils meeting API Service Category SF may be used where API Service Categories SE, SD or SC are recommended.

To "Motor Oil Guide, part 2"