Hi all yup I am a new owner of the van. I am so not sure what to expect except that it eats loads of gas. I here you can put a chip in it to regulate the gas if that true?

 

Nope.

 

The best way to get great gas mileage with an over 4000# vehicle is to take the actual mileage add 50% to it and tell the world that is what you get if good mileage is important to you!
On a serious note, make sure everything is stock then the lightest accelerator push gets the best mileage.
What exact mileage do you get?
Our expedition with the 4.6 ltr got 14.5 mpg for many miles.
Our F350 ford with a 460 V8 never got to 11 MPG on the freeway.
Our 2013 Nissan Versa, tiny car tiny engine has averaged 35 MPG for it's first 1500 miles.
Our 1500 5.9 van got 15.5 MPG at 60 MPH for a tank of gas.
Our 73 dodge dart with a 375 HP 450 CI and an torque auto got 13.3 MPG on a 3500. trip.... the dart only weighs 3200#
Please observe that the 1500 5.9 dodge got better than the 4.6 ltr ford.
The expedition all jazzed up weighs about the same as the 1500 and takes about the same power to operate thus the same mileage.
There ain't no free lunch, large vehicles are expensive to operate.
That's why I own the little econo box for daily driving!!

 

Note that miserable as the gas mileage is, it's probably no better or worse than full size vans by Chevy or Ford are getting today !
Replacing plugs, wires, cap, rotor, might get you a couple of more MPG's.