Figure 8-3. Sources of Oil Contamination
rust, corrosion, wear, oil oxidation, and thickening at high
protection to the engine against bearing scuffing,
temperatures. There are currently six oil classifications
corrosion, and oil oxidation.
for gasoline engines (SA, SB, SC, SD, SE, and SF) and
four classifications for diesel engines (CA, CB, CC, and
(3) SC. Meets all automotive manufacturers'
CD). The higher the alpha designation, the higher quality
requirements for vehicles manufactured from 1964 to
the oil is.
b. API Designations.
(4) SD. Meets all automotive manufacturers'
requirements for vehicles manufactured from 1968 to
(1) SA (Utility Gasoline Engines). Adequate for
1970. SD oil offers additional protection over SC oils that
utility engines subjected to light loads, moderate speeds,
is necessary with the introduction of emission controls.
and clean conditions. SA-rated oils generally contain no
(5) SE. Meets all automotive manufacturers'
requirements for vehicles manufactured from 1971 to
(2) SB (Minimum Duty Gas - Automotive).
1979. Stricter emission requirements create the need for
Adequate for automotive use under favorable conditions
this oil to provide protection during these years.
(light loads, low speeds, and moderate temperatures)
with relatively short oil change intervals. SB-rated oils
(6) SF. Meets all automotive manufacturers'
generally offer minimal
requirements for vehicles manufactured