Porsche 968 - Engine Oil Viscosity and Types; Understanding Oil Viscosity; Single-grade and Multigrade Oils; Light Running Oils for Fuel Saving

Vluo•llv
lttl:tllt• lltlt·. vi•,.tntt•, w l1 1' 11 co ld , .tlld tllin bodied ' Oils with two vi scos ities are called multigrade
wltt'll W111111 llltl Vl',c cl' .tly ol dll oil ts expressed oils; oils with only one viscosity are termed
lty tl•, '•/\ 1 c l.t ~:. I 01 co ld vi scos ity the SAE s ingle -g rade oils.
Slngle-grade/MuHigrade Oils
1 1.1',', t•, H!Vt•n '"' c1 IIUfllb cr a nd the letter " W"
(,1', 111 Wlll lt •t ), lor ll ot viscosity the S AE class is
HIVI'II !lilly dS d number.
lite vtscosity of an oil is, therefore, always the
same for a s pecific temperature range if it has
th e sa me number of an SAE class.
E.g.: A 10 W-30 oil and a 10 W-40 oil have the
sa me viscosity when cold; when hot the oil with
the number 30 is thinner than the oil with the
number 40.
Light Running Oils
Light running oils are of lower viscosity at all
temperatures and therefore make it possible to
save a certain amount of fuel.
Light running oils, which have to be suitable for
year-round use, require a particularly high ther-
mal stability .
Oils with this kind of performance are non-con -
ventional engine oils and are termed "all season
fuel economy oils" in the Porsche approval.
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