I am currently looking at a 1986 F250 XLT 4x4 with the auto tranny and a 6.9 L Diesel. What kind of gas mileage can I expect with this particular vehicle when empty? I have heard that it should pull between 15 - 20 when empty on the highway. True?

 

yea u should see like 14mph,,, 20 would kinda streching it , unless they leaned the pump way out , which would make it a slug