Thanks for the correction! I was not thinking back that far. The burning diesel fuel aggrevated the Hindenburg fire, but high octane gasoline would have made it a true inferno!
The train does not get a 100 miles per gallon. It uses something like a gallon or two for every ton of freight per 100 miles. It accomplishes that by economy of scale, 50mph speeds, 0-50 in twenty minutes or so and pretty much constant speeds.