Porsche Boxster Owner's Manual page 203

Always observe the following points:
– Use engine oils approved by Porsche only. This
is a precondition for optimum and problem-free
operation of your vehicle.
– Regular oil changes are part of servicing.
It is important that the service intervals,
particularly the oil change intervals, are
observed in accordance with the specifications
in the "Maintenance" booklet.
– Oils approved by Porsche can be mixed with
each other.
– Porsche engines are designed so that no oil
additives may be used.
– A label is located in the engine compartment,
which provides you with information on suitable
oil for your engine.
Your Porsche partner will be pleased to
advise you.
Oil change
The engine oil has to be changed regularly at the
intervals listed in your Maintenance Schedule.
f Please see the chapter "CAPACITIES" on
Page 281.
We recommend that you have the engine oil
changed at your Porsche dealer, who has the re-
quired oils and the necessary filling equipment.
If you suspect an oil leak in the engine have your
dealer check it out immediately.
All current engine oils are compatible with each
other, i.e. when making an oil change it is not nec-
essary to flush the engine if you wish to use a dif-
ferent brand or grade of oil.
Since, however, each brand of oil has a special
composition, you should, if possible, use the
same oil brand if it becomes necessary to top up
between oil changes.
Porsche engines have long intervals between oil
changes. You can make best use of these long oil
change intervals by using multigrade oils since
these are largely independent of seasonal fluctua-
tions in temperature.
If your vehicle is used frequently in stop-and-go
traffic in cold weather, the engine will not always
be properly warmed up.
Condensation from products of combustion may
accumulate in the oil. In this case, it is advisable
to change the oil more frequently so that your
engine once again has 100% efficient engine oil.
Engine oil performance class
Engine oil is not only a lubricant, but also serves
to keep the engine clean, to neutralize the dirt
which penetrates into the engine through combus-
tion and to protect the engine against corrosion.
To perform these functions, the oil is provided with
additives which have been specially developed for
these functions.
The efficiency of an oil is expressed, for example,
by the API, ILSAC or ACEA classifications.
Viscosity
Like all liquids, engine oil is viscous when cold,
and thin-bodied when warm. The viscosity of an oil
is expressed by its SAE class. For cold viscosity
(measured at temperatures below 32 ° F/0 ° C) the
SAE class is given as a number and the letter "W"
(as in winter), for hot viscosity (measured at
212 ° F/100 ° C) the SAE class is given only as a
number.
The viscosity of an oil is, therefore, always the
same if it has the same number of an SAE class.
Oils with two viscosities are called multigrade oils;
oils with only one viscosity are termed single-
grade oils.
Single-grade oils can not be used in your engine.
The viscosity of the engine oil for your Porsche
has to be chosen according to the ambient tem-
perature given in the engine oil recommendation
table.
Maintenance, Car Care
201