The unit value is a constant defined by the module (since 1.3.1). With Joomla! you can override this value. Follow the instructions:
- Login into your Joomla! administrator console > Extensions > Languages manager > Overrides
- Click the New button
- Language constant: enter the needed value:
- PEC_M_SPN_UNIT_USER_KM to override the km value
- PEC_M_SPN_UNIT_USER_MI to override the mi value
- PEC_M_SPN_UNIT_USER_NM to override the nm value
- Text: enter the replacement value, like 'kilometer' or 'miles' or what you want
- Save
Now the new value is displayed in the frontent. You can update the module, this value will be preserved.