I put it in to a full batch of bio, still in the processor and around 50C. Mix for 20mins then pump out to storage.
It doesn't appear to vaporise but decomposes (violently) around 100C so below that should be fine
MPG is definitely better in the Audi and RangeRover with 2EHN than without by 2 or 3 (which is significant when the vehicle is only doing low 20s anyway)