what is the flash point on gasoline?

Question

if you had a small fuel leak from the block and puddled on the manifold at what temp would the engine start a fire

Answer 1

The flash point of a flammable liquid is the lowest temperature at which it can form an ignitable mixture with oxygen. At this temperature the vapor may cease to burn when the source of ignition is removed. A slightly higher temperature, the fire point, is defined at which the vapor continues to burn after being ignited. Neither of these parameters is related to the temperatures of the ignition source or of the burning liquid, which are much higher. The flash point is often used as one descriptive characteristic of liquid fuel, but it is also used to describe liquids that are not used intentionally as fuels.

Petrol:
Flash point: >-45 °C (-49 °F)
Autoignition temperature: 246 °C (475 °F)

Diesel:
Flash point: >62 °C (144 °F)
Autoignition temperature: 210 °C (410 °F)

Jet Fuel:
Flash Point: >38 °C (100 °F)
Autoignition Temperature: 210 °C (410 °F)

Answer 2

Petrol (gasoline) is designed for use in an engine which is driven by a spark. The fuel should be premixed with air within its flammable limits and heated above its flash point, then ignited by the spark plug. The fuel should not preignite in the hot engine. Therefore, gasoline is required to have a low flash point and a high autoignition temperature.

Petrol (gasoline):
Flash point: >-45 °C (-49 °F)
Autoignition temperature: 246 °C (475 °F)
Diesel:
Flash point: >62 °C (144 °F)
Autoignition temperature: 210 °C (410 °F)
Jet Fuel:
Flash Point: >38 °C (100 °F)
Autoignition Temperature: 210 °C (410 °F)

Answer 3

Gasoline is a mixture of different hydrocarbons ranging from butane (C4) up to about C12. Gasoline has to vaporize when it's mixed with air in your engine so it has to be fairly volatile, that also contributes to a low flash point.

Answer 4

-49 F