I don't want to complicate things too much, Jeff. This is just a simple diversion. Something to kill some time.

Give everyone a gas station to fill at, and have a driver's meeting somewhere within a couple miles of there. Seal their gas caps and launch them rally-style at a 1-2 minute interval.

Have some checkpoints more as places to gather and eat and BS than anything else.

Then end at a gas station to fill up each car and determine the results.

I don't particularly want to play the E85 game, or really even diesel unless I have to. It would add hassle to my logistics. But, if I did go there... I'd still only be looking at gallons consumed. This isn't about the politics of what the fuel is or where it's from, just a simple competition for some local guys to entertain themselves.