Honda 2013 NSS300 Owner's Manual page 27

Instruments
U type only
Shows average fuel consumption in ℓ/100km
based on the tripmeter A.
After you reset the tripmeter A, the average
fuel consumption meter shows "
24
".
RESET
KO type only
Shows average fuel consumption in km/ℓ
based on the tripmeter A.
After you reset the tripmeter A, the average
fuel consumption meter shows "
RESET
".