Vapor Lock with 912iS. Most probable location?

RW,

Here in the USA the1.0 PSI RVP waiver for ethanol fuels only applies to summer fuels, which is less critical because even with the waiver the limit is 9 PSI in some states like CA, and 10 in less restrictive states. Not as good as AVGAS, but acceptable.

In the transition and winter months these restrictions are lifted and all fuels are expected to meet the ASTM class C or D standard. The class C standard applies to transitional months and targets 11.5 PSI.  The class D standard is for the summer months and targets 13.5 PSI. The exact dates for transition months and summer months are defined differently by various jurisdictions.  Knowing what you are getting can be difficult. I buy my fuel in batches of 40 gallons and I test the RVP when I buy in the transition months. It’s an easy test done at home once you learn how. Here in the USA I am eager to see the Swift UL94 product available at more locations so we can be done with all this.