fuel additives AUDI S4 2008 Owners Manual

Fuel and filling the tank251
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Fuel and filling the tankPetrolApplies to vehicles: with petrol enginePetrol grade
The correct grade of petrol is listed inside the fuel tank
flap.The vehicle is equipped with a catalytic converter and must only be
run on unleaded petrol . Unleaded petrol must comply with the
European EN 228 standard. The petrol grades have different octane
ratings (RON). If, in exceptional circumstances, the correct octane
rating is not available, please note the following:•
For engines which require Premium unleaded petrol (95 RON)
according to ⇒page 323, “Performance, weights and dimensions”:
Regular unleaded fuel with 91 RON can also be used. This will,
however, result in a slight loss of power.
•
For engines which require Super Plus unleaded petrol (98 RON)
according to ⇒page 323, “Performance, weights and dimensions”:
Premium unleaded fuel with 95 RON can also be used. This can,
however, result in a slight loss of power under certain driving condi-
tions. – If premium unleaded petrol is not available, the engine can
be run on regular unleaded petrol with 91 RON as an emergency
measure . In this case only use moderate engine speeds and a light
throttle. Fill up with premium or Super Plus petrol as soon as
possible.Caution
•
Petrol complying with the EN 228 standard can contain small
quantities of ethanol. However, “bioethanol fuels”, which are
retailed under various different names such as E50 and E85, and
which contain a large proportion of ethanol, must not be put into
the vehicle, as this would damage the fuel system.
•
Even one tankful of leaded fuel would permanently impair the
efficiency of the catalytic converter.
•
High engine speed and full throttle can damage the engine when
using petrol with an octane rating lower than the correct grade for
the engine.
DieselApplies to vehicles: with diesel engineDiesel fuel
Please note the information on the inside of the fuel tank
flap.Diesel fuel must comply with the European EN 590 standard. It must
have a cetane number (CN) of at least 51. The cetane number indi-
cates the ignition quality of the diesel fuel.
Winter-grade diesel
Diesel fuel can thicken in winter. For this reason petrol stations in
some countries also offer winter diesel.
Caution
•
The vehicle is not designed for the use of biodiesel (FAME fuel).
The fuel system would be damaged if you used biodiesel.
•
Do not mix fuel additives (“thinners”, petrol or similar additives)
with the diesel fuel.
•
If poor-quality diesel fuel is used, it may be necessary to drain
the water separator on the fuel filter more frequently than is speci-
fied in the Service Schedule. We recommend having this done by a
specialist workshop. If water is allowed to collect in the filter, this
can cause engine performance problems.
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