Volvo XC90 Owner's Manual page 148

06 Starting and driving
Refuelling
IMPORTANT
•
Always refuel with unleaded petrol so
as not to damage the catalytic con-
verter.
•
Do not use additives not recom-
mended by Volvo.
Catalytic converter
The purpose of the catalytic converter is to
purify exhaust gases. It is located in the flow
of exhaust gases close to the engine so that it
quickly reaches operating temperature. The
catalytic converter consists of a monolith
(ceramic or metal) with channels. The channel
walls are lined with a thin layer of platinum/
rhodium/palladium. These metals act as cata-
lysts, i.e. they participate in and accelerate a
chemical reaction without being used up
06
themselves.
Diesel fuel may contain a certain amount of RME, but further amounts must not be added.
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146
TM
Lambda-sond oxygen sensor
The Lambda-sond is part of a control system
intended to reduce emissions and improve
fuel economy.
An oxygen sensor monitors the oxygen con-
tent of the exhaust gases leaving the engine.
This value is fed into an electronic system
that continuously controls the injectors. The
ratio of fuel to air directed to the engine is
continuously adjusted. These adjustments
create optimal conditions for efficient com-
bustion of harmful emissions (hydrocarbons,
carbon monoxide and nitrous oxides) using
the three-way catalytic converter.
Diesel
Diesel must meet the EN 590 or JIS K2204
standards.
IMPORTANT
Only ever use fuel that fulfils the European
diesel standard.
IMPORTANT
Diesel type fuels which must not be used:
special additives, Marine Diesel Fuel, fuel
oil, RME 1 (Rape Methyl Ester) and vegeta-
ble oil. These fuels do not fulfil the require-
ments in accordance with Volvo recom-
mendations and generate increased wear
and engine damage that is not covered by
the Volvo warranty.
Diesel engines are sensitive to contaminants,
such as excessively high volumes of sulphur
particles for example. Only use diesel fuel
from well-known producers. Never use diesel
of dubious quality.
At low temperatures (-40 °C to -6 °C), a par-
affin precipitate may form in the diesel fuel,
which may lead to ignition problems. Special
diesel fuel designed for low temperatures
around freezing point is available from the
major oil companies. This fuel is less viscous
at low temperatures and reduces the risk of
paraffin precipitate.
IMPORTANT
Use special winter grade fuel during cold
months.