Fiat 500 2018 Owner's Manual page 301

Units
After pressing the "Units" button on the touchscreen, you
may select each unit of measure independently displayed
in the instrument cluster display. The following selectable
units of measure are listed below:
Setting Name
After pressing "Custom" on the touchscreen, you may
select from one of the below menu items:
Setting Name
Fuel Consumption
Temperature
Pressure
US
Metric
Selectable Options
Changes the instrument cluster display to US units of
Changes the instrument cluster display to Metric units of
Selectable Options
MPG (US)
MPG (UK)
°C
psi
MULTIMEDIA 299
measure.
measure.
L/100 km
km/L
°F
kPa
10