I called customer service at Cfmoto today and spoke with a gentleman named Evan. I told him that the manual for my 2021 CForce 500 recommended 5w40,10w40 or 15w40 based on ambient temperature. He told me that some models require a JASO rated motorcycle oil but the 500 doesn’t have a wet clutch. He said to use any automotive 10w40 that meets the current automotive spec for that oil. He told me that there is no need to run a synthetic but if I do I should wait until after a couple of oil changes without synthetic. So if I plan on riding this summer with temps in the 80’s and up, would it be ok to run a 15w40 that is also rated for gas engines? And my next question is I see a bunch of guys, even dealers, using K&N and HiFLo 152 filters in their bikes. I haven’t found any aftermarket filter that actually crosses to the Cfmoto. Is it ok to use an aftermarket filter on these machines? I can do an oil change with a K&N filter and rotella for under 20 bucks compared to 37 with dealer stuff.