Thought of this when commenting on the Zoltar Miracle Trike:
The Ecomodder fe prediction spreadsheet is a wonderful tool- takes a lot of onerous calculations away!
But one limitation of it is, the values given are valid for steady-state, super calm and perfect conditions. As an example, I plug in the values for my Sport Coupe and get what I think are realistic predicted fe values at the steady state speeds, but tank-to-tank proven fe never matches that (nor should it) due to the real world getting in the way.
So I looked at it a bit and it seems in the case of my Sport Coupe I have to knock 10-15% off the predicted fe to get the real world fe.
That is with normal attentive conservative driving, not extreme P&G, of course.
I wonder if that 10-15% correction factor is valid for everyone else's predicted/real fe too?