Be careful with the type of PVC pipe that you use for the cold air kit. I had a home made kit on my 2000 4.7, and it worked great for 3 years. I guess the heat made the PVC brittle and a piece of it broke off and entered the throttle body. Jammed the throttle while going down the interstate. Scared my wife to death. Was a real pain in the butt to clean all of that out of there. Only real damage was that a rocker arm got knocked off somehow. I've gone back to the stock intake system with the K & N filter.

 

Hmmmm....

I justinverted my stocker to do the same. I works in the 1998/1999 model 5.9L only.

 

Our best fuel economy in our 2002 D SLT+ w/5.9, AWD, 142,000 miles has only been 14mpg running 55 mph in Kansas (dead flat) on cruise control. We are running full synthetic 5w-30, air filter gets changed every other oil change, new plugs, wires, cap and rotor, trans filter was changed at 135,000 miles. I haven't yet changed the oil in the differentials. It runs like a scalded dog and purrs like a kitten. 80 percent of its driving is highway.

 

Cyclopsblown134,

At 142k miles, I would recommend you to have the dif fluids changed, it's way past its maintenance schedule! When you change the fluids in the dif, make sure to change out the fluid in your transfer case also. I think the transfer case uses the same fluids as the tranny.

 

Thanks, I'll probably change the fluids in them in the next couple of weeks to synthetics.

 

If you are trying to save gas money, then you don't want to spend more than you will quickly recover in mpg savings. Even a drop-in K&N will probably cost too much to recoop the cost in mpg savings.

Here is my list of 5 things:

1. New plugs.
2. New air filter.
3. Increase tire pressure to max pressure allowed by tire and check tire pressures weekly.
4. Keep your foot out of it while you accelerate.
5. Slow down. 60 mph will get you probably 1 mpg more than 70 will.

If you are really that worried about it, buy a Honda.

 

holy old thread, i havnt seen this one in a LONG time


damn but yea the best thing to get better mpgs is to keep up on the maintance keep the tires inflated as much as possible w/o wearing the tires poorly and put a brick under the gas pedal(keep your foot OFF the floor, i know its hard but this works)

 

Keep your foot off the pedal? HUSH YOUR MOUTH! That's a big part of the joy of these things, they friggin scoot and are fun to drive. I enjoy driving our D more than any other sport ute we've owned or currently own.

 

gr8scott,

I do recommend a K&N filter over a paper filter anyday, not mainly because of the slight mpg saving, but because of the longterm savings of having to continously replace the paper filters. I usually change out my paper filters in DFW area annually. You count the cost of around $15-$20 a pop, over a period of 9 years that I own my D, it would have costed me close to $200. But I replaced it with a OEM K&N. To this day, it's still the original, just take it out of the box and wash it every 20k or whenever it starts to look dirty. Bought this OEM K&N filter for $55 from NAPA.

So get the best of both worlds, K&N can get you up to 1 mpg better fuel savings as well as long term savings of not having to constantly buy new filters. Plus, you will feel a little quicker throttle response too.

 

If your D does not have an electric fan you can gain Mpg by installing one. I have been reading a lot about this topic.
The best electric fans produce around 5000-6000 cfm
Clutch fan delivers 12,000-15000 cfm (this seemed a little high to me but thats what they said) I also seen 4000 cfm at "idle" for a clutch fan.

With that information I have been debating to make the change..