Autoignition Temperatures of Common Vehicle Fluids

Vehicle Environments


The autoignition temperature measurements important to fire investigators are those that best reflect the circumstances found in the vehicle operating environments. Because there are enormous variations in the environments, there are also wide variations in the potential ignition temperatures. The following table gives values for the various fluids under different conditions.

Fluids Autoignition Temperature oF
Automatic Trans. Fluid 580 to 1120
Brake Fluid (DOT 3) 520 to 1065
    Ethylene Glycol (100%) 950 to 1245
    Ethylene Glycol (50%) 775 to >1200
    Propylene Glycol (100%) 960 to 1020
    Propylene Glycol (50%) 975 to 1065
Diesel Fuel 950 to >1200
    Biodiesel (B100, B20) 705 to 1300
Ethanol 1260 to 1330
Gasoline (87-92 octane) 1135 to1550
    Gasoline blend (E85) 1300 to 1325
Lubricating Oil 580 to 1130
Power Steering Fluid 590 to >1200


To construct this table, all sources were combined to establish the ranges. While concise in what it presents, this method also hides some inconsistencies between published test results. For example, some researchers reported that gasoline would not ignite up to 1200 degrees F., while others had ignition at 1100 degrees F. (The notation, “>1200,” indicates there was no ignition when the tests were stopped at 1200 degrees F.)

If you would like more information about fluid ignition measurements, sources, the test conditions and results, click here.