There is another hot engine alternative to gasoline (may not work anymore, but was used a primary fuel in the early days of autos), and that is Kerosene. I DO NOT recommend this because most Kerosene is for off road use and therefore illegal to use on road. In the early days of automobiles you started up and warmed up your engine on gasoline and switched to kerosene for normal operation.
I DO NOT recommend this for a few reasons:
1. If may not work with modern cars.
2. Kerosene is dangerous as well, but not as dangerous as gasoline
3. Most consumer Kerosene is for Off Road Use (and illegal for environmental and TAX reasons).
4. Due to reason 3 such a recommendation would run afoul of CPF rules.
MODS:
1. If such information is considered in violation of CPF rules despite my warnings please delete this message without further notification.
2. Please excuse (or edit if really needed) my attention getting caps.