SMART fortwo cabriolet Operator's Manual page 216

Service fluids and capacities
214
Anticorrosion/antifreeze
Your vehicle contains a number of
aluminum parts. The use of aluminum
components in motor vehicle drive systems
necessitates that anticorrosion/
antifreeze coolant used in such drive
systems be specifically formulated to
protect the aluminum parts.
Failure to use such anticorrosion/
antifreeze coolant will result in a
significantly shortened service life.
Therefore, the following product is
strongly recommended for use in your
vehicle: MB 325.0 Anticorrosion/
Antifreeze agent.
Before the start of the winter season (or
once a year in hot southern regions), you
should have the anticorrosion/antifreeze
concentration checked.
The coolant is also regularly checked each
time you bring your vehicle to an
authorized electric drive smart center for
service.
Anticorrosion/antifreeze quantity:
Cooling system
Approximate freeze protection
-35¦ (-37¥)
approx. 3.9 US qt
(3.7 l)
-49¦ (-45¥)
approx. 4.3 US qt
(4.1 l)