I have no idea about internet etiquette so I apologize for any forum faux pas. My old lady has a 2000 Excursion with 7.3L. Like the rest of the world I am trying to get more fuel efficency from it. When I ask the "old timers" they say to put a new intake system on and free up the exhaust to get better milage. They say programmers and chips are a waste of money when you are only looking for economy. Many diesel "doctors" used to dealing with the modern engines say that the programmers will help with milage and give you the extra HP as a bonus. Any advise from any of you? I have read through many threads and done quite a bit of research both on and off the internet, but still can't get any clear answers.

Another question: What is the sensor in the side of the stock airbox? Does it get moved or affected when an aftermarket air box is put on?

Yes, this is for my wife, My trucks are sitting in the back forty and replaced by a VW!

 

Modifying the intake and exhaust is to allow the engine to breathe better. On a completely stock engine these mods really won't give you any increase in mileage or power since the factory intake and exhaust is plenty enough. Once you add a chip or programmer, then the benefits of a bigger intake and exhaust really do show. Remember that adding any power will increase the temps inside the cylinders since most will do a combination of increased fuel injection and advanced timing. Basically a chip or programmer is what will help with milage, provided that you keep your foot out of the pedal (sooooooo hard to do with all that extra power).

You should have two sensors on the side of your airbox. One is a temp sensor, the other is a filterminder. With an aftermarket intake, these are pretty much rendered useless, and actually mostly useless to begin with. The temp sensor is only effective in colder weather in determining the high idle mode and exhaust backpressure activation. Both of mine are zip tied out of harms way.

 

eatfish,

Both the old timers and the new techies are correct you can get MPG with either or both plans. A diesel uses 8-10 times the air of a same size gas engine doing the same work. The bets way to better efficiency is to get more air thru it as air is still free and creates a more complete combustion which gets you more BTU use of the same amount of fuel. The stock air system is great at stopping dirt but poor at flowing the amount of air a diesel would like to use. In fact Ford tells you to leave the stock filters in waaaay to long especially on the new 6.0. I replaced mine at 8000 miles and saw a 2 PSI boost increase with the new stock filter, much less when I changed to an AFE Stage I I got an extra 3 PSI from that!
If you unplug the front end the exhaust is the next item to go as it just became the cork, if you cut the factory muffler up and tried to breath thru it underwater you'd have a hard time of it the louvers are very very small and they clog up over time and get even smaller. We get customers that do intake and exhaust and report back with a 1-2.5 MPG increase with regularity.

Now if you go with a programmer like a Superchip or Predator or Evloution they all change the pulse width, timing and duration of the injection cycle. This will also make MPG if you drive it liek you want to make MPG. If you drive it like you stole it, then you'll break even but have a good time while doing it though! I tell customers all the time, don't lie to me or yourself and don't bother to check MPG for at least two tanks, because you're gonna play with the HP and it won't register as MPG till you drive it normally. After 2 tanks you'll have worn the "new" off of it and be ready to make MPG instead of smoke!!

Call us if you have questions, we have all the quality brands and will be glad to help you.

Mark @ DPPI

 

Hmmmm, after about 30 tanks the "new" still hasn't worn off for me.