PEUGEOT 508 Handbook page 204

Practical information
Fuel used for petrol engines
the petrol engines are compatible with
e10 type petrol biofuels (containing 10 %
ethanol), conforming to european standards
eN 228 and eN 15376.
e85 type fuels (containing up to 85 % ethanol)
are reserved exclusively for vehicles marketed
for the use of this type of fuel (BioFlex
vehicles). the quality of the ethanol must
comply with european standard eN 15293.
202
Fuel used for Diesel
engines
the Diesel engines are compatible with
biofuels available at the pumps which meet
current and future european standards:
- Diesel fuel that meets standard eN 590
mixed with a biofuel that meets standard
eN14214,
- Diesel fuel that meets standard eN16734
mixed with a biofuel that meets standard
eN14214 (possibly containing up to 10 %
Fatty Acid Methyl ester),
- Paraffinic Diesel fuel that meets standard
eN15940 mixed with a biofuel that meets
standard eN14214 (possibly containing up
to 7 % Fatty Acid Methyl ester).
DIESEL
the use of B20 or B30 fuel meeting standard
eN16709 is possible in your Diesel engines.
However, this use, even occasional, requires
strict application of the special servicing
conditions referred to as "Arduous conditions".
For more information, contact a PeugeOt
dealer or a qualified workshop.
the use of any other type of (bio)fuel
(vegetable or animal oils, pure or diluted,
domestic fuel...) is strictly prohibited (risk of
damage to the engine and fuel system).
Only the use of Diesel fuel additives that meet
the standard B715000 is authorised.