[chris]

Re: High speed mileage

Fortunately, this formula does not work for me.
Last weekend I got 47mpg on a 400-mile roundtrip, almost all highway, load 3 adults and 1 child, very light a/c use, mostly steady speeds between 65-75 mph, rare overtaking, outside temp around 65F.

It has been my experience that the average mileage for any sustained speed is not a regular function. It is something like this:

       | s < 20       55
m(s) = | 20 < s < 40  55 - (s - 20)*(7/20)
       | s > 40       303/sqrt(s)