Wendy
It would help if we knew the premise that requires evap rate for 100LL.
In example,"..... the aircraft had been sitting for months on the ramp
and the fuel had evaporated leaving sticky residue.....". That is far
fetched but not entirely inaccurate either.
Lots of great experience here to draw on so ask away. If someone
presents a silly or inaccurate postulation it will receive lots of
comment!
Old Timer