Gambarshu

A higher viscosity oil, such as 10w30, will flow slower at low temperatures compared to a lower viscosity oil like 5w30 This is important because viscosity changes as temperatures changeThe main difference between 10W30 and 10W40 motor oil is that 10W40 has a higher viscosity, which means that it will remain thicker at higher temperatures than 10W30 Viscosity means a liquid's resistance to flow, and normally a higher viscosity is a good thing for oil, as it acts as a better lubricant and creates a stronger sealI'm thinking these little primitive engines should be just fine on 10w30, and being so little on the cc's, the rider would benefit from a lower viscosity oil Castrol 4t 10w 40 Ctx 700 Forum 10w-30 10w-40