This is Turtle.
Trucks only , you can put the tail gate down but succure any load or
items or you will get a unsuccure load ticket for it. Really just take
everything out of the back and put the tail gate down. Now this being
done on trucks traveling high speeds like 60 to 70 MPH . it can save 1
mile to the gallion in some cases.
Also air your tires up to the max. pressure stated on the tire it'self
and it will increase the mileage per gallion.