I calculated the MPG of my '85 El Camino based on a recent road trip.
About 150 miles of highway driving at 60-75MPH, burning roughly 24 gallons of 87 octane gasoline (I have since switched over to 89 octane by suggestion of others, and to get a slight uppity to my sagging RPM's when at idle, among other reasons). By my (most likely wrong) calculations, my vehicle gets around 6.5 MPG gallons highway, and probably around 5 MPG city.
This wouldn't be a giant problem if