Alfa Romeo 2015 4C Owner's Manual page 151

UNDERSTANDING YOUR INSTRUMENT PANEL 149
System Maintenance
In winter, the climate control system must be turned on at
least once a month for about 10 minutes. Have the system
inspected at an authorized dealer before the summer.
NOTE: The system uses R-1234yf and R134a coolant
4
which does not pollute the environment in the event of
accidental leakage. Under no circumstances should you
use R-134a fluid which, in addition to being incompatible
with the system's components, contributes greatly to the
greenhouse effect.