Dear i purchased GS-150 In Jan-2015, I changed the Suzuki Original Oil with (Mobil 1 Racing 4T) at the time of purchase. But Now have Sold out my bike after using only 800km. I run my GS-150 on 110 -115 Km/h after only 400 Km Running.
There was no any sound change of my bike not only one time, many times i run my GS-150 more than 100 Km/h there was no any issue.