Honda NSS250A Owner's Manual page 104

Your scooter does not need oil additives.
Use the recommended oil.
Do not use API SH or higher oils
displaying a circular API ''energy
conserving'' service label on the
container. They may affect lubrication
and clutch performance.
NOT RECOMMENDED
Do not use non-detergent, vegetable, or
castor based racing oils.
Engine Oil & Strainer Screen
Other viscosities shown in the following
chart may be used when the average
temperature in your riding area is within
the indicated range.
OK
Servicing Your Honda
95