Some good ideas from the old Mobil Economy Run:
Mobil Economy Run - Wikipedia, the free encyclopedia
That Rambler American in the upper right looks exactly like my first car - a 1961 Rambler American. It got 30 MPG when I first got it. The top speed was 60 MPH because the throttle linkage would not allow full power. When I fixed the linkage, the mileage dropped to 24 MPG.