I wonder what's the cause for the squiggle in the MPG graph in post #5.
In reality its not all that big, ~2 MPG, ~5%.
It could just be the result of it being only a single data run.
But I can accept that it happening just as the graph turns downward
may be more than just coincidence.
A +1 MPG adjustment at 45 MPH and a -1 MPG adjustment at 50 MPH would
show what I would consider to be a much more likely MPG graph.
Would access to a BSFE chart shed light on whats going on?
An inquisitive but semi-informed mind would like to enquire.