The Inter-American Development Bank sponsors an annual race called the Greaseball Challenge in which cars modified to run on biofuels set off southwards from Washington DC in the general direction of Costa Rica. I wonder how many make it all the way to San José? It probably helps that the vehicles are supposed to be a bit beaten up to start with.
The rules are clear about pit stops:
"Greaseballers will source their fuel from a number of greasestops on the road: biodiesel producers, diners, fast-food outlets, supermarkets, factories, and farms. The possibilities are endless, and rather daunting. It’s a challenge."
Here's an interview with one of this year's partcipants, Suzanne Ward.
There's a movie in here somewhere...