looking to increase my (gas) mpg.

[arirama]

2004 ford excursion eddie b. v10 gas with a 4.1 rear. i do some city and highway driving around 75 mph. been averaging aprx. 10 to 12 mpg. pending on brand of fuel i use how can i get better mpg? oh its a 4x4.

[mark v]

Keep the vehicle in tune. Check air filter, keep oil changes regularly.

Make sure tires are inflated to the proper PSI that is stated on the drivers door or drivers door jamb.

Keep the pedal off the metal.

[theoldwizard]

Slow down ! Drive 65 mph. You will be surprised at how much that will save.

Changing from a 4.10 final drive ratio to a 3.55 on both differential will save gas, but you will have to drive a long, Long, LONG way before you'll get your money back.

In general, buying a new car is not a good solution to fuel cost issues, but in your case, if you can downsize a long way, say to an Escape 4 cylinder (even with AWD) it would pay back in a few years.

[geovex]

If you're looking for aftermarket improvements, I've personally had decent gains out of the following:
Pulestar Sparkplugs
K&N Stage3 Air Intake and Filter
Helical Throttlebody Spacer
Exhaust cutout behind the cat
Superchips Flashpaq Programmer

Along with everything that Mark V said.

You have to be the decider on whether or not its worth it. It will significantly improve performance!

[mark v]

Reflashing the computer is probably your best gain i bet?