Thanks to you all for your comments and input, some of it very scientific. In the end what bothers me is that the vehicle was advertised at sale for 32mpg be it Imperial (Canadian) or American gallons; and that the Ford dealership can hook it to a computer and come up with 30mpg at 60mph: and then advise to just try to drive a consistent 60mph to prove their point, I don't know how prevalent this type of disparity is with other car makers or for that matter other Ford products, but I may just spend some internet time to learn more.
Jeff