|
Base Oil Category |
Manufacturing
Method |
Oil Characteristics |
|
Group I |
Solvent Freezing |
Group I base oils are the least refined
of all of the groups. They are usually a
mix of different hydrocarbon chains with
little or no uniformity. Due to their
instability and poor overall properties,
most of today’s engine oils use very
little, if any, Group I base oils. They
are generally used in less demanding
applications. |
|
Group II |
Hydroprocessing and
Refining |
Group II base oils
are common in mineral-based motor oils
currently available on the market. They
have improved lubricating performance
over Group I base oils in areas such as
volatility and oxidative stability. They
have fair to poor performance in areas
such as pour point and cold crank
viscosity. |
|
Group III |
Severe Hydroprocessing and Catalytic
Dewaxing |
Group III base oils are subjected to the
highest refining levels and while they
originate from crude oil, they are
chemically rearranged to offer molecular
uniformity and stability for very good
performance in a wide range of
lubricating properties. They are
commonly marketed as synthetic or mixed
with lower group base oils and marketed
as semi-synthetic products. Group III
base oil products are increasing in
popularity. |
|
Group IV |
Chemical Reactions |
Group IV
Polyalphaolefins (PAOs) are chemically
engineered synthetic base stocks. When
combined with additives, they offer
excellent performance over a wide range
of lubricating properties. They have
very stable chemical compositions and
highly uniform molecular chains. Group
IV base oils are commonly found in
automotive and industrial applications. |
|
Group V |
As Indicated |
Group V base oils include all remaining
non-synthetic and synthetic oils such as
white oils, esters, silicones, and
polyalkylene glycols. Esters are common
Group V base oils used in lubricant
formulations. Esters exhibit a wide
variety of properties specific to each
individual product. They are often used
like additives to enhance the properties
of other base oils. |
