Volvo XC90 Owner's Manual page 275

11 Specifications
Fuel
When driving in temperatures above +38 °C,
fuel with the highest possible octane rating is
recommended for optimum performance and
fuel economy.
Petrol: Norm EN 228
11
IMPORTANT
Use only unleaded petrol to avoid damaging
the catalytic converter. In order for the Volvo
warranty to apply, never mix alcohol with
petrol, the fuel system could be damaged.
Diesel
The diesel engine's fuel system is sensitive to
contaminants, see page 199.
Diesel: Norm EN 590 or JIS K2204
274