In large scale I'd agree that only using vegetable oil for car fuel seems like bad idea, because we seem to be running out of food at that point. But using elec

In large scale I'd agree that only using vegetable oil for car fuel seems like bad idea, because we seem to be running out of food at that point. But using electricity conversed to hydrogen with relatively bad efficiency (70%) we are soon running out of electricity too. Combine that with hopefully shift from fossil fuels to renewable, and the shit we are in deepens. Now if you could use batteries and electric cars for short trips you would have very high efficiency. Then shift to refueling capable system for long range needs. This is only possible if the "long range" system has very low infra needs. Optimally we would have some kind of standard that would allow you to swap battery to fuel tank + fuel cell unit in your electric car. I've ranted about that previously. https://news.ycombinator.com/item?id=10942912 https://news.ycombinator.com/item?id=10942912