my manual says I can use about any weight oil. I'm useing cas. 10/30 now.
so why all the different weights?( my a.t.v. is a foot shift)

Thanks in advance.[img]i/expressions/face-icon-small-smile.gif[/img]

 

It depends of the range of temperatures that your going to ride in. The air temps that is, I have an o4 eiger. I'm running 20-50 mobil super syn in it. It gets really hot here in california, also being that the bike is air cooled, I wanted to run high quality oil in it. There's a chart in your owners manual that shows the temp ranges along with the corresponding weights of oil to use.

 

yes I know about the temp. My question is, why use 20/50 if 10/40 will work? (curious)
Thanks in advance.

 

20/50 oil has 20 wieght base stock, with modifiers to get to 50 wieght when hot.
10/40 has 10 weight base stock and modifiers to get to 40 weight when hot.
So using a 20/50, the oil wont thin below 20 weight oil, and gives better lubrication at higher engine temps.

 

Honda buster said it all.