I have a 2006 Ford 500 with the CVT tranny AWD version; a good condition high mileage car.

In October I was driving on a nicelevel freeway with light traffic, so I recorded
the fuel MPG at several different freeway compatible speeds when using cruise control.
The car was hauling two adults and a full load of luggage.

The graph shows cruising speed vs. fuel economy; about 70F temp -
while on a straight & level road, the best case scenario.




For the whole car trip vacation the entire trip mpg was 24 - 25.
Around town I'm getting 18 - 19.

 

Not entirely unknown, but very interesting and informative, thanks for the info.