[Funny]

Just to throw in my two cents...

What I think you guys are looking for is the auto-ignition temperature as compared to flash point. Below is a quote from the Wikipedia article on Flash point.

Examples of flash points
Fuel; Flash point; Autoignition temperature
Ethanol; 12.8°C (55°F); 365°C (689°F)
Gasoline (petrol); <−40°C (−40°F); 246°C (475°F)
Diesel; >62°C (143°F); 210°C (410°F)
Jet fuel; >38°C (100°F); 210°C (410°F)
Kerosene (paraffin oil); >38–72°C (100–162°F); 220°C (428°F)
Vegetable oil (canola); 327°C (620°F)[1]
Biodiesel; >130°C (266°F)

"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.

Diesel is designed for use in a high-compression engine. Air is compressed until it has been heated above the autoignition temperature of diesel; then the fuel is injected as a high-pressure spray, keeping the fuel-air mix within the flammable limits of diesel. There is no ignition source. Therefore, diesel is required to have a high flash point and a low autoignition temperature.

Diesel varies between 126°F and 204°F (52°C-96°C/WJ). Jet fuels also vary greatly. Both Jet A and jet A-1 have flash points between 100°F and 150°F (38°C-66°C/WJ), close to that of off the shelf kerosene. However, both Jet B and FP-4 have flash points between -10°F and +30°F (-23°C - -1°C/WJ)"