translation.en: Saving or displacing barrels for 25 bucks rather than buying them for over a hundred, adds up to a $4 trillion net saving counting all the hidden costs at zero. So to get mobility without oil, to phase out the oil, we can get efficient and then switch fuels.
translation.zh: 每桶油能省下25美元 而不再花去一百多元钱 忽略隐性成本的话 净节约额将达到四万亿美元 所以为了让交通业摆脱对石油的依赖 终结交通的石油时代 我们需要增加效率，并改变能耗方式