I don't know, my '78 1.i litre Ford Fiesta would do 80 all day long and still get 40mpg. Wasn't slow uphill either. I don't think there's many Euro models that can't cruise at the legal limit without issue. Hell, even my nasty, buzzy little VW Polo, 850cc's would do 70 all day, just in a rather annoying way. Never had a car more reliable, or that I hated so much.
Best car I ever had was my gorgeous '87 Ford Capri 1.6 . Quite nippy and again, would return 35 mpg at a steady 80mph.
Those are examples of very old technology, which has since been far surpassed.
It doesn't help that most U.S. drivers wouldn't consider a manual gearbox either, they are just way more economical, despite what the manufacturers will try and tell you, especially city driving.
I had a 76 VW Golf 1-5 Auto, that did a dismal 14mpg average U.K. Urban driving. Small motors and Auto transmissions just don't work, in my opinion.