This chapter is a departure from prior discussion of practical fuels and energy sources for automobiles. It presents and discusses some lesser-known fuel options that are independent of the petroleum supply chain, allowing them to be used in times of fossil fuel scarcity or unaffordability. Some have a positive environmental profile, but most are neither energy or environmentally sustainable. Included are homemade ethanol and methanol, wood gas, waste vegetable oil (WVO), biomethane, and acetylene. There are others, but this recitation is limited to those that have had a non-trivial level of public adoption at some time. The focus is restricted to combustion fuels that, with modifications to the engine and fuel system, can replace gasoline or diesel fuel in conventional ICE vehicles. None are legal for on-road use in the USA or Western European countries. But this coverage is important because these fuels serve as testaments to human ingenuity in desperate times.