From what I see here, my best bet is to do the following:
1: No vehicle, -ever- gets filled from anything but a pump nozzle at the gas station.
2: Have some reminder that the Fuse is diesel, to make sure to pull up to the right pumps, regardless of color on the handle. The fact that the color on the fuel door is green helps there, as well as the fact that gassers don't have a pee can inlet cap by the fuel receptacle.
3: Fill up vehicle. Close fuel fill door and end transaction. Then, fill up the gas cans. Since I use premium unleaded for the generator (and create a new transaction for this), this addresses the fuel type issue for the cans.
4: Nobody fills up the vehicles except me.
I do like the idea of carrying extra propane, because it cuts out having to carry a generator and cans. However, I would have to find a welder who is willing to fab me a hitch mounted cargo rack that has the proper vertical supports for propane cylinders. As an alternative, I could use a hitch mounted cargo carrier and a Manchester rack that is used on RV tongues which supports 20# or 30# containers... but it would have to be modified or adapted to bolt to an existing hitch cargo rack, and done in a way that will stand the rigors of the road (high test fasteners, all bolts/nuts getting LocTite Red), etc.
