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Gasoline vapour pressure

Gasoline vapour pressure

I need information on gasoline vapour pressure at different temperature, in particular in the 20°C to 80°C range.
I only find data at 100°F and that is not enough for my calculation purposes.
Any suggestion where I can find detailed abacus?


RE: Gasoline vapour pressure

First, because by definition, the Ried Vapour Pressure stated in literature is ONLY at 100F.  

Second, gasoline is a mixture of hydrocarbons, so there is no fixed value of a TRUE VAPOUR PRESSURE (thats the name for a vapour pressure at differnt temperature).

I ran a simulation on a mixture and got the following:  For a 10 pis RVP, the true VP was 5.2 psia at 20 C and 33 psia at 80C.  This is an example only, you need to do your own bubble point flashes on your composition.

RE: Gasoline vapour pressure

Gasoline RVP varies by local statute, season & altitude.  You can buy different RVP test fuels for hot start testing, etc.  You might want to contact Chevron Phillips or other fuel suppliers for more details.

RE: Gasoline vapour pressure


As noted by dcasto, Reid Vapor Pressures (RVP) are always at 100 deg F. And as noted by dgallup, the RVP of a gasoline varies by season, region, altitude and local regulation.

The U.S. Environmental Protection Agency's publication "AP-42: Compilation of Air Pollution Emission Factors", Chapter 7, Table 7.1-2, publishes the True vapor pressures (in psia) at 40, 50, 60, 70, 80, 90 and 100 deg F for gasolines having Reid Vapor Pressures of 7, 7.8, 8.3, 10, 11.5, 13, 13.5 and 15.

That Table 7.1-2 is at:

If your need for such data is for calculating vapor emissions from gasoline storage tanks, then the EPA also provides a software program called TANKS which can be downloaded at

Milton Beychok
(Visit me at


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