Hi Andy, I am fairly confident the Mash you are looking at uses a copy of a Honda engine. In a Honda, it was used in a 90's trail bike .... the XR 400 ...... and also in a Japanese / American model, the CL400. They are different beasts completely from an XBR. I know that Mash advertise one particular machine as a 500...... That only differs from the Roadstar cosmetically. It still uses the 400 ( 397cc ) engine. As for oil, it has been said on here many times that oil is cheap. I fully agree with this thought ..... Filters are cheap as well. Always go for decent oil of the correct spec , and change it often. I am sure one long trip wouldn't hurt it though. Regards, Tony