Vauxhall Omega Owner's Manual page 217

Inform ation on AC EA oil grade
cla ssific ation
The Association d es Constructeurs
Européens d'Autom ob iles classifies engine
oils according to their perform anc e
(grade).
Ea ch class is identified by letters and
numbers, e.g. A3.
The letter indicates the field of application:
A = Petrol eng ines in passenger cars
B = Diesel engines in passenger cars
E = Diesel engines in trucks
The number shows the grade in
numerically ascending order.
Informat ion on SAE oil gra de
classificat ion
Engine a nd transmission oils are grouped
in SAE c lasses by the
Society of Automotive Engineers based on
their viscosity. Viscosity is the measure of
interna l friction of the oil in flux, dependent
on its temperature.
The SAE classification does not provide
information on the quality of the oil; it
merely indicates the range of application
of the oil dependent on the outside
temperature – see diagram.
The first number indicates v iscosity at low
temperatures (cold sta rt behaviour). The
second num ber indicates visc osity a t hig h
temperatures.
Do not sw itch to a different viscosity in the
event of brief temp erature fluctuations.
A = S AE classes for petrol eng ines
B = S AE classes for diesel engines
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