most often required. Make sure to follow the manu-
facturer’s recommendations for lubricant types.
Engine oils
Generally, all liquid lubricants are called oil.
They may be mineral-based (including petroleum
bases), natural-based (vegetable and animal bases),
synthetic-based, or emulsions (mixtures).
Engine oil is classified by two standards: the
American Petroleum Institute (API) service classi-
fication and the Society of Automotive Engineers
(SAE) viscosity rating. This information is on the
oil container label. Two letters indicate the API ser-
vice classification (SF, SG, etc.). The number or se-
quence of numbers and letter (10W-40 for example)
is the oil’s viscosity rating. The API service classifi-
cation and the SAE viscosity index are not
indications of oil quality.
The service classification indicates that the oil
meets specific lubrication standards. The first letter
in the classification (
S
) indicates that the oil is for
gasoline engines. The second letter indicates the
standard the oil satisfies.
Always use an oil with a classification recom-
mended by the manufacturer. Using an oil with a
different classification can cause engine damage.
Viscosity is an indication of the oil’s thickness.
Thin oils have a lower number while thick oils have
a higher number. A
W
after the number indicates
that the viscosity testing was done at low tempera-
ture to simulate cold-weather operation. Engine oils
fall into the 5- to 50-weight range for single-grade
oils.
Most manufacturers recommend multigrade oil.
Multigrade oils (10W-40, for example) are less vis-
cous (thinner) at low temperatures and more vis-
cous (thicker) at high temperatures. This allows the
oil to perform efficiently across a wide range of en-
gine operating conditions. The lower the number,
the better the engine will start in cold climates.
Higher numbers are usually recommended when
operating an engine in hot weather.
Greases
Grease is an oil to which a thickening base has
been added so the end product is semi-solid. Grease
is often classified by the type of thickener added,
such as lithium soap. The National Lubricating
Grease Institute (NLGI) grades grease. Grades
range from No. 000 to No. 6, with No. 6 being the
thickest. Typical multipurpose grease is NLGI No.
2. For specific applications, manufacturers may rec-
ommend a water-resistant type grease or one with
an additive such as molybdenum disulfide (MoS
2
).
Brake fluid
Brake fluid is the hydraulic fluid used to transmit
hydraulic pressure (force) to the wheel brakes.
Brake fluid is classified by the Department of
Transportation (DOT). Current designations for
brake fluid are DOT 3, DOT 4 and DOT 5. This
classification appears on the fluid container.
Each type of brake fluid has its own definite char-
acteristics. Do not intermix different types of brake
fluid. DOT 5 fluid is silicone-based. DOT 5 is not
compatible with other fluids or in systems for which
it was not designed. Mixing DOT 5 fluid with other
fluids may cause brake system failure. When add-
ing brake fluid,
only
use the fluid recommended by
the vehicle manufacturer.
GENERAL INFORMATION
7
1
10
Rounded edges
Sharp edges
Direction of thrust
9
Full support
areas
Direction
of thrust