Here’s the combined world energy flow in 2007:The unit, PJ, is in petajoules. Ford and his new company charged ahead making gas-powered cars, but at the time, gas cars were hardly the norm. Suddenly, a lot of the things that sucked about gas cars didn’t suck anymore—and they had become much cheaper than electric cars. The cost of driving a gas car is harder, because gas prices and car fuel efficiency widely vary. The best case scenario for a gas car is unusually cheap gas (let’s say $1.40/gallon) coupled with unusually high fuel efficiency (let’s say it’s a rare gas car that gets 35 mpg).