Gary’s Q&A

Listener question & Gary’s response · Transcript passage

With that, let’s start with the first question, which comes from therat_mafia on Discord, who asks, I recently re-watched Back to the Future 3, and something occurred to me that I never considered the last time I watched the movie 20 years ago. Why didn’t Doc Brown distill his own gasoline? Crude oil was relatively accessible, and surely they had access to kerosene for mining lamps. Isn’t oil refining just about heating the oil to a certain temperature?

You are correct that distilling petroleum is really just a function of heating petroleum in the absence of oxygen. Different heat levels produce different types of fuel, such as kerosene, gasoline, diesel, and jet fuel. The process is called fractional distillation.

I think it is fair to assume that Doc Brown would have known that if he was smart enough to discover time travel.

However, I would disagree about the accessibility of oil. According to the movie, Doc Brown traveled back to Hill Valley, California, in 1885. Hill Valley is fictional, but Back to the Future 3 was filmed in Sonora, in the Central Valley, so let’s assume that it is somewhere around there.

The first oil well in California was only drilled in 1876, nine years before Doc arrives in the past. The best information I can find is that several hundred barrels per day were produced in California around 1885.

So he probably could have easily ordered a single barrel of oil and had it shipped by train. Approximately 20 gallons of gasoline can be produced from a barrel of crude petroleum, and the DeLorean had a 13.5-gallon gas tank. In theory, you could distill gasoline from something akin to an alcohol still, but it might be dangerous and inefficient.

So, yes, that could be done, but it would take time; hijacking a train is much easier and makes for a better story.