Welcome to the Green Iron Addiction Support Group
Make plans now for the GA Rally......it's the most fun you can have without removing your pants.
When we speak of adding motor oil we are speaking in the context of used motor oil...unless you have access to very cheap new motor oil.
You can run a fairly high concentration of UMO and some people claim to run 100%....I would not reccomend that.
My favorite mix is used motor oil, waste veggie oil, diesel fuel and a little regular unleaded gas to thin it out.
The deuce is very forgiving about fuel as long as you keep the water out.....always carry extra fuel filters just in case.
Using off road fuel is a judgement call...you save a few bucks per tank but if you ever get dipped the fine will cancel out any savings you see. Adding UMO to mask the color will not work nowdays since they use a floresent dye that can be detected with a black light.