Fully synthetic oil is a by-product of petroleum whereas semi-synthetic oil is the combination of crude minerals and petroleum.Both possess good lubrication characteristics but the main advantage of semi-synthetic is cost reduction.
But think ahead that it is also just more important to take care of what grade you going to use.
There are many grade in selecting the oil. The grade just simply tells you about the condition of surrounding temperature that the oil will suit perfectly for the use. Technically you call that as the viscosity of that oil. so that is very important.Also check the specification sheet of your bike manufacturer that what grade they are suggesting for their machines optimum performance.
For example the manufacturer specifies that JASO or API on their engine oil specification.So it is better to go by the standard they are preferring for choosing the engine oil.
For example you may have to option of choosing
- Motul 20W-40
- Turbo Plus 20W-40
- Turbo Active 20W-40
- shell semi synthetic 5W-40
- Veedol 20W-50
But choose with in the grade limits and certification limits that your manufacturer prefers / specifies for the optimum result of your bikes performance.