Brian said:
That explains a lot, as trip computers are not always accurate unless
you average the mileage over several tanks of gas. It's more accurate to
calculate the mileage manually (distance divided by gallons at fill-up).
Averaging that over several tanks improves accuracy, too.
In my opinion, the latter is the only really good way to compute average
MPG. And mileage varies widely based on a number of factors. I had an
84 Accord that would get 36 typically on the interstate at 60 or so.
Yet one day I got 46 MPG on a full tank. Believe me?
How about if I tell you I was driving across the upper midwest on very
flat terrain, at 55 MPH ... with, and I'm not exagerating, a 50-60 MPH
direct tailwind! It was eery. The car was almost silent at 55 MPH as
the relative wind speed was varying between probably -5 and +5 MPH. It
sounded like you were sitting still revving the engine a little. It is
amazing how much noise the wind makes at normal cruise. And with the
wind drag virtually gone, the mileage is truly impressive.
Matt