Volvo XC90 Owner's Manual page 139

IMPORTANT
•
Always refuel with unleaded petrol so as
not to damage the catalytic converter.
•
Do not use additives not recommended
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/rho-
dium/palladium. These metals act as catalysts,
i.e. they participate in and accelerate a chem-
ical reaction without being used up them-
selves.
1 Diesel fuel may contain a certain amount of RME, but further amounts must not be added.
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 content
of the exhaust gases leaving the engine. This
value is fed into an electronic system that con-
tinuously controls the injectors. The ratio of fuel
to air directed to the engine is continuously
adjusted. These adjustments create optimal
conditions for efficient combustion of harmful
emissions (hydrocarbons, carbon monoxide
and nitrous oxides) using the three-way cata-
lytic converter.
Diesel
Diesel must meet the EN 590 or JIS K2204
standards.
IMPORTANT
Only ever use fuel that fulfils the European
diesel standard.
06 Starting and driving
Refuelling
IMPORTANT
Diesel type fuels which must not be used:
special additives, Marine Diesel Fuel, fuel
1
oil, RME (Rape Methyl Ester) and vegetable
oil. These fuels do not fulfil the requirements
in accordance with Volvo recommendations
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 paraffin
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 tem-
peratures and reduces the risk of paraffin pre-
cipitate.
IMPORTANT
Use special winter grade fuel during cold
months.
06
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