http://en.wikipedia.org/wiki/Flash_point
Gasoline (petrol) −43 °C (−45 °F)
Diesel (2-D) >52 °C (126 °F)

The flash point is not to be confused with the autoignition temperature, which does not require an ignition source, or the fire point, the temperature at which the vapor continues to burn after being ignited. Neither the flash point nor the fire point is dependent on the temperature of the ignition source, which is much higher.

http://en.wikipedia.org/wiki/Autoignition_temperature
Gasoline (Petrol) 247–280 °C
Diesel or Jet A-1 210 °C
Hydrogen 536 °C