Changing engine oil grade is always a experiment, you have to analyse the difference at own risk and enjoy the benefits or loss.
The first no. 0,5,10,15,20 indicates the oil thickness (oil has to be thin) in (W)winter season(that's why their is W in the middle of oil grade), there's specifications available on internet, Thin oil easily flows through oil galleries (inside the engine). If oil is not thin enough the oil film formation (lubrication) between piston and cylinder is not sufficient which cause metal to metal friction.
Last digits 30,40,50 indicates the oil thickness (oil has to be thick) at engine operating temperature(when engine is hot), if thickness is not enough then enough amount oil film will not forms, which causes again metal to metal friction.

All this engineering stuff is taken into account while making engine's. But some experiment in engine oil can be done (experiments but within the tolerance).

In your case you have changed the grade from 10W50 to 20W50 Which is not good as currently due to winter engine temperature quite low rather than summer (depends upon you area).

If you are happy with Motul then this is the right time switch back.

धन्यवाद विशाल वाघासाहेब 👍

Thanks for all the technical details ... Help me to understand the oil grade..

It's been over a 3 week and I am feeling high vibration while riding .... Heavy engine noise along with no smoothness ... But other hand engine is heating less with rapsol 20w40 grade....

Still motul is the best option ... Thanks for your advise


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