So depends upon your riding method. But RE suggests for Interceptor/GT 650 oil change at 10000 Kms with 10w50 Full Synthetic Oil @ Prajwal | Hey I filled 20w50 to my continental gt 650 recently am ...

The recommended engine oil grade for the RE Interceptor 650 is 10W50 API SL (or higher), JASO MA2, Synthetic. We would suggest you to go with the recommended oil grade for apt performance.