1999 Dodge Dakota
 

I have a 1999 Dakota 4.6 4x4.....was wondering what are some simple eco mods i can do to improve mpg....fastest i go is 60 and get about 17 mixed highway/town

As far as simplicity it is going to be the same mods everyone suggests
1) bed cover, not a cap unless it is an aerocap
2) smooth wheel covers
3) lowering or arch gap fillers as found on our list 65+ Vehicle modifications for better fuel economy - EcoModder.com
4) buy a FE gauge
5) adjust the nut
6) fill up tires

if im not mistake your truck should have an electric fan and engine driven fan on my friends we pulled the engine driven fan and swapped in a set of under drive pulleys at the same time and he got 2-4 mpg. in the 2 years since we pulled the engine driven fan the electric fan rarely ever comes on

I don't think so. E-fans started getting installed on Dakotas, only beginning in the 2000 model year.

That being said, it should easily be possible to retrofit an e-fan to OP's Dakota. Though I am not familiar with a 4.6L engine in a Dakota. 1999 model year Dakotas came with a 2.5L I-4, 3.9L V6, 5.2L V8, or 5.9L V8.

Hmm other than those mentioned gear up or get a larger diameter back tire if rpm is high on interstate., front spoiler or air dam. dont forget that a more efficient engine makes better use of its fuel, my 99r/t has come a long way with no special mods; well sorta for a gas sucking pig truck.

Grille blocks (as much as you can)
Air dam (Can do with lawn edging for <$20)
Wheel covers (coroplast cut into circles and zip tied to spokes)

And cover the rear half of the bed, if you're not up to making an aero topper. GM holds a 1984 (?) patent on covering the rear half, claiming it's more efficient than covering the whole thing. By any account, the differences are pretty close. But buying a half sheet of plywood is cheaper!
http://ecomodder.com/forum/member-sv...ture4138-a.jpg

Covering the bed (even covering just the rear half) does not work with 3d generation Dakotas.