Well after looking up Bio-Diesel, it has the advantage that a lot of the base product used is so called 'waste oil' that is left over from cooking. So after you fry up your Iguana-On-A-Stick, that oil can be made into Bio-Diesel. The question I would ask is that recycling would be a mandated way of life in a Fury Road world, so getting people to recover their cooking oil for bio-diesel production is easy to see, but is it enough to power the vehicles of the civ? Probably not so you'd need to have some sort of negative food effect to represent acreage devoted to veggie farming where the food isn't going to be used. Although I would think that even if the veggies aren't eaten by people, the rind and pulp left over after the pressings could be fed to livestock and thus cutting down on the amount of hay and the like they would need. Now you know my view on resources that plant based since why can you only have corn in one square and not the one right next to it? It's just stupid. However, if we remained chained to that outmoded Civ tradition p) having a corn resource would allow you to produce gasahol. As much as I like the civic idea, I can't really see enough difference you'd have in power. From what I've read, it would seem likely that the first vehicles would be powered by Gasahol and/or Bio-Diesel since they can be made from products easily grown and a vehicle that is designed to run on Diesel won't 'care' if it's bio or regular diesel. The only downside to bio-diesel I can find is that by it's nature it attracts water and thus can easily allow water into the engine system which causes problems. Plus, due to it's different chemical make-up, it tends to wear out rubber seals and the like faster than petroleum based oil. So perhaps when a Civ is using bio-fuels, their maintenance cost would be higher for their vehicles.