! Do not refuel with low-grade fuel and do
not use fuel additives that are not tested
and approved for Mercedes-Benz vehicles.
Damage to or malfunctions of the fuel
system may otherwise occur.
DEF
Important safety notes
i For BlueTEC vehicles only.
DEF is a non-flammable, non-toxic, colorless,
odorless and water-soluble fluid.
! Rinse surfaces that have come into
contact with DEF immediately with water or
remove DEF using a damp cloth and cold
water. If the DEF has already crystallized,
use a sponge and cold water to clean it. DEF
residues crystallize after time and
contaminate the affected surfaces.
High outside temperatures
If DEF heats up to over 122 ‡ (50 †) for
extended periods, e.g. as a result of direct
sunlight on the DEF reservoir, DEF can
decompose. Ammonia vapors develop as a
result.
GWARNING
When opening the filler cap of the DEF tank
ammonia gas vapors may escape. Refill DEF
in a well ventilated area only. Ammonia gas
vapors have a pungent odor and are
particularly irritating for your skin, mucous
membranes, and eyes. Inhaling ammonia gas
vapors will cause burning eyes, nose, and
throat, as well as coughing and watering eyes.
Low outside temperatures
DEF freezes at a temperature of
approximately 12 ‡ (–11 †). The vehicle is
equipped with a DEF preheating system when
it leaves the factory. Winter operation is
therefore also guaranteed at temperatures
below 12 ‡ (–11 †).
Additives
! Only use DEF in accordance with ISO
22241. Do not use additives with DEF and
do not dilute DEF with water. This may
destroy the BlueTEC exhaust gas
aftertreatment system.
Purity
Assuring the purity of DEF is particularly
important with respect to avoiding
malfunctions in the exhaust gas
aftertreatment system.
If DEF is pumped out of the DEF tank, e.g.
during repair work, it must not be returned to
the tank. The purity of the fluid can no longer
be guaranteed.
! Impurities in DEF (e.g. due to other
service products, cleaning agents or dust)
lead to:
R increased emission values
R damage to the catalytic converter
R engine damage
R malfunctions in the BlueTEC exhaust gas
aftertreatment system
Engine oil
Please bear the following in mind
The engine oils are matched to the
performance of Mercedes-Benz engines and
service intervals. You should therefore only
use engine oils and oil filters that are
approved for vehicles with maintenance
systems.
For a list of approved engine oils and oil filters,
consult an authorized Mercedes-Benz Center
or go to the Internet site
http://www.mbusa.com (USA only).
! Never use engine oil or an oil filter of a
specification other than is necessary to
fulfill the prescribed service intervals. Do
not change the engine oil or oil filter in
order to achieve longer replacement
Service products and capacities527Technical dataZ
