i also use bel ray 90w. it works great imo. i change my oil once every 3 months and it is still almost the same color as when i put it in brand new. but this topic has been covered about once a week man. youre a new b so i aint gonna be a dick, but just letting you know man if you ever want to know the answer to a question before you ask, use the search button on top of the page.