I have read countless threads on other forums, about this however I am not having much luck seeing it talked about here (i may not be putting the right search terms in.
I have an Auto, 2003 Dakota Quad 4.7 V8, I just bought from my brother
So I have come to the conclusion that the following may help from the consensus of other forum threads.

K&N Filter
This is my primary question, would I be smarter to get the whole intake system or just the drop in, some people report a +1-1.5 increas putting these in, and I was just about to order one last night until I saw they have complete systems in the $100 + range, wonder if that is any better, then I read people saying do NOT get K&N because it lets more crap into your engine and then the oil goes in as well and mess up the MAF or MAP (I dont know what that is)

Switching to Synthetic Lubricants
I read one guy in a thread who kept stating he realized a 2-5 mpg gain when adding synthetic lubricants, however he kept mentioning red line specifically I almost wonder if he has a stock in the company, and he was talking more specifically about standard vehicles.

Changing plugs
I dunno where I begin on this, I read that everyone that did this were not impressed and switched back to the factory ones as their mileage actually decreased.

Removing weight
I have read some people have removed something on the truck that is typically very heavy and replaced it with a electric version that is much lighter, I wanna say it is the clutch fan but I assume that would only apply to standard vehicles.

So that's all I know, anyone can help me out tell me if the full KN system is worth it or the drop in or if what I read was true that some sensor will get screwed up in the long run.

I have tried to adjust my habits, and do as much coasting as I can, and I dotn drive like crazy, and I will be adding a soft tonnaue cover when I get it from my brother. It is quite a shock to go from averaging 17+ MPG in my old S-10 to seeing 13.1 avg on the onboard mpg calculator, (MY s-10 I would divide the miles I got of the tank by how many gallons I just added)

Any insight?

 

Sounds like you done all you can. Just remember it is a truck with a V8. Not a Honda Civic with a 4cly. If you want better MPG sell the truck. I will move this post to the 2nd Generation Dakota sub-forum.

 

Then K&N wont make hardly any difference and it passes a lot more dirt than a paper filter.

Changing to synthetic certainly can't hurt, but don't expect a noticeable gain.

Most times fancy plugs don't help anything and often run worse, stick to factory.

Your best bet is a free flowing exhaust but again the difference is small if anything.

A clutch fan is not a fan for a clutch, it uses a clutch to engage and disengage depending on temperature. Running an electric fan only may free up a little mileage.

The mods I have done to my truck at the most have helped maybe 2MPG and that's only highway, no way in hell I've made any of that money back. The ones that help were exhaust, intake manifold and roller rockers, the last 2 you can't do to your 4.7. My mods are fairly substantial and the difference was a little. Don't go expecting huge changes by doing small things.

Another thing is tire size. Even the stock tires are too big for the stock 3.55 gears IMO, it'll lug the engine around too much. Something to consider would be running smaller tires or putting in 3.92 gears but doing gears isn't cheap.

 

No Im gonna agree with crazy, get a car. Trucks are never going to get good MPG and thats just how it is.

I kept my truck when I got the subbie, I need a truck and thats that. I know it gets bad MPG its a 4000lb+ block of steel with a horridly under powered V6. I get about 20mpg (and thats now 96% highway) and 13mpg sounds like its on the low side to me. Just keep up on your maintenance and drive it nice.

 

I will probably get flamed for this.

The BEST thing you can do is buy this thing (attachment)


It is good for about 20% MPG increase at 70 MPH.


Block your grill with something, and make an air damn to block air from going under the truck. The things that really suck gas on trucks are its aerodynamics. If you get the drag down, gas mileage will go up.

 

The attachment isn't working. And blocking your grill would NOT be smart.

Like the OP said, losing weight helps, but if you take out your spare don't get a flat.


And something so many people over look is tire pressure. If your tires are under inflated you could lose considerable mpg. Make sure they are almost at max (especially now thats its getting cold out) and you may see a big difference if they were all low.

 

I would say a good electric fan is a good investment. Not sure what kind of MPG gains you will see but it should help out a little. And of course the exhaust mods are going to help that engine breathe out a little better but i think thats about it. A intake might help a little as well but you can read the post above and figure out whats best for you.

I have a 2000 crew cab 4x4 4.7 and i mix most of my driving about 50/50 and get i would say some where in the high teens most of the time on 31s.

 

Tire pressure isn't as important as aerodynamics. In the winter, if you have ice or snow, I would not run near max PSI.

 

tire pressure is free, that cap is hideous and expensive.

 

Check for equal tire PSI
A drop in filter wont do anything, if anything get the full cold air intake system (ebay normally has good deals)
An exhaust system that doesn't restrict air flow
Do a full tune up (plugs/wires when required, serpentine belt..maybe get a shorter belt and skip your a/c if you have it, check your pulleys to make sure theres very little or no restriction)
Change your rad fan to an electric fan
Remove all excess weight; I would strongly advise against removing your spare tire, as paying for a taxi/tow truck/being late for work will cost you more money than you'll save by removing it
Get a tonneau cover
Get lighter, street tires
Drive like a grandma, go 55-60 insted of 65-70
Thats all the basic/cheapest things that you can do for a little bit of power/mileage increase, if you wanted more power and an increase of mileage you could go with a supercharger, get a standard transmission, change your gearing, etc etc etc, but its not worth it at all just to gain a few mpg

If you buy one of these things at a time, you wont really notice a difference at all, but when you put them all together it makes a little bit of a difference.
I've done all of the basic stuff above, except I bought a canopy in sted of a tonneau cover. Theres a definate increase of power and I get like 1-2mpg extra in the city and 3-4 extra on the highway, unless I take advantage of the power ripping it around everywhere then im lucky to get 170 miles to a tank. All city driving I get 190 miles to a tank, 95% highway and 5% city im now getting 230ish