Thursday, September 25, 2008
Vapor recovery is not an issue for running E85 in a non-FFV
One of the claims against running E85 in a non-flex-fuel vehicle is that ethanol has a higher vapor pressure than gasoline, and thus you will get a check-engine-light when the vapor recovery system is overwhelmed.
As you can see from the graph above, that is not quite true. In fact, E10 has a higher vapor pressure than just about any mixture of E85 and gas that you could come up with.
From the graph (which is from an SAE paper), I would say that even running straight E85 will not throw a code from the vapor recovery system.