Originally Posted by Hexaflouride

I filled up the 1978 6.9 today after going through a full tank for the first time with a working odometer. It's my habit to check the MPG's after each fill up for my cars. I was pleasantly surprised to see 19 MPG, which I think is fantastic for a 37 year old, 6.9L, 2 ton, V8 sedan. My daily commute is 16 miles one way on mostly local 55 MPH highways. What do you get for fuel economy, average and all-time best?