Just bought and 2002 F350 crewcab 4x4 7.3l.
Just want to know what chip is better to get for fuel mileage and power power is good now nothing has been done to it. yet

 

That is a can of worms. Lots of opinions here on that subject. It will help us help guide you, if you let us know what you plan on doing with your truck, ie: towing moderate to heavy, daily driver, etc.

I personally have been very happy with my DP tuner. They have great customer service and are the sponsor of this forum. In order for you to get a chip from most manufacturers, you will need supporting mods. Gauges (exhaust gas temperature, tranny temp, and boost are most common) are a must unless you go with a programmer that has monitoring functions. You will need a better intake, and exhaust as well. These engines, like all engines, are just basically big air pumps, so the more you can bring in efficiently, the more you need to get out efficiently.

Even if your only goal is better fuel economy, you will want better intake and exhaust. The 60 economy and 80 economy tunes are good for mileage if you can manage to keep your foot out of the pedal. But be forewarned, once you chip the truck, you will have a hard time doing that though. The truck will really wake up. You think it has good power now...

 

This question is like starting up a conversation about politics or religion.

Chipping, gadgets, and snake oil will not improve fuel economy, no matter what all the ads say. It takes ww horsepower to go xx MPH, and it takes yy fuel to push our 4-ton bricks that fast for zz miles. Depending on temps, road conditions, wind, vehicle condition/configuration, and most importantly - your right foot, you can expect 15 - 19 MPG from a stock-configured truck with a 3.73 rear end. A little less than that with a 4.10 rear end. I get 17-18 with my daily driving because I'm a light foot, but my truck is configured to get nasty when I choose. If I show you the photos of what "Stinky" can do in a nasty mood, it will likely cost you a lot of money from the bad case of the highly-contagious PMS (Powerstroke Mod Syndrome) you will likely catch.

That being said, the Custom Tunes link in my signature below will give you a lot of the information you're looking for.

 

Your absolute best chance of retaining fuel mileage is leave the stock tire size on it. Like Tugly said there are many factors that can have effects on mileage. Fresh oil, clean filters and anything with a grease fitting should be greased is a good start.

As for Chips or Programmers....... Good Luck!!!!

 

Chips, programmers and tuners are well worth the cost for waking up the power potential of the 7.3 with a little informed shopping to select the right one.

However they will do absolutely nothing on their own to improve mpg, although some of the common supporting mods may slightly.

The trick to getting The best economy is the same for our trucks as anything. Proper tire inflation, good oil and clean filters, a sensible driving technique and most important of all resisting the urge to turn your truck into a bro dozer.